20th Conference of Czech and Slovak Physicists

7 Sept 2020, 08:00 → 10 Sept 2020, 16:30 Europe/Zurich

 

 

 

 

 

 

 

Již 20. konference českých a slovenských fyziků proběhne ve dnech 7.- 10. září 2020 v Praze. Spolu
s Českou fyzikální společností JČMF a Slovenskou fyzikální společností vás na ni zve i Matematicko-fyzikální fakulta Univerzity Karlovy, v jejíchž prostorách se bude konference tentokrát konat. Pracovními jazyky budou angličtina, čeština a slovenština.

Konference si již tradičně klade za cíl seznámit účastníky s nejnovějším pokrokem zejména v odvětvích fyzikálních věd, kterým se v České republice a na Slovensku intenzivně věnujeme. Chceme posílit také komunikaci fyziků napříč obory a napříč generacemi.  Pozornost bude věnována i výuce fyziky a prezentaci fyziky pro širokou veřejnost. Konference bude publikovat e-sborník příspěvků. Sborník bude recenzovaný a bude mu přiděleno ISBN.

Konference získala záštitu Primátora hl. m. Prahy a záštitu Velvyslance Slovenské republiky v České republice.

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Czech Physical Society, Slovak Physical Society and Faculty of Mathematics and Physics, Charles University cordially invite you to attend the 20th Conference of Czech and Slovak Physicists, to be organised in Prague from 7th to 10th September 2020.

This joint conference primarily aims at the latest advances in the branches of physics to which our countries intensively contribute. We also wish to strengthen communication in physics across different fields of interests as well as across generations. Attention will be paid to physics teaching and to physics outreach, too. A conference e-proceedings will be published. The proceedings will be peer reviewed and will be identified via ISBN.

 The conference is held under the auspices of the Mayor of Prague and the Ambassador of Slovakia to the Czech republic.

20KCSF_abstrakty_zborniktiskovaverze_korekce.pdf

20KCSF_abstrakty_zborniktiskovaverze.pdf

Plakát KCSF

sbornikkonference.pdf

Záštita Magistrát hl.m. Prahy.pdf

Záštita velvyslanec SR.pdf

Monday 7 September

1 Registration

2 Welcome

Plenary Talks

3 Magnonic Analog of Black/White-Hole Horizons in Superfluid 3He-B

Súčasné technológie neumožňujú experimentálne študovať a overovať naše teoretické modely
a predstavy o fundamentálnych fyzikálnych javoch prebiehajúcich v takých astro-fyzikálnych
objektoch, akými sú čierne diery. Zatiaľ jediným spôsobom ako experimentálne verifikovať
tieto modely (a predstavy) o fyzike čiernych dier je nájsť laboratórny fyzikálny systém, ktorý
s istými obmedzeniami umožňuje simuláciu vlastnosti čiernych dier. Cieľom prednášky je
prezentovať ako teoretický model, tak aj experimentálne výsledky získané na novom
fyzikálnom systéme umožňujúcom simuláciu vlastností horizontu udalostí v čiernych/bielych
dierach. Modelový systém je založený na jave spinovej (magnónovej) supratekutosti v
supratekutom 3He-B. Ako experimentálny nástroj, ktorý modeluje vlastnosti
čiernych/bielych dier sme využili tzv. spinovo precesujúce vlny šíriace sa na pozadí
spinového toku medzi dvoma Bose-Einsteinovými kondenzátmi magnónov vo forme
homogénne precesujúcich domén. V súhlase s teoretickým modelom sme experimentálne
ukázali formovanie a prítomnosť horizontu udalostí pre spinovo precesujúce vlny, vrátane
efektu zosilnenia týchto vĺn. Vzhľadom k tomu, že experiment je realizovaný pri teplote
blízko absolútnej nuly (600 μK), prezentovaný modelový systém tak umožňuje aj štúdium
spontánneho Hawkingovho žiarenia.

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The current mankind technologies do not allow experimental study and thus verify our
theoretical models and concepts on fundamental physical phenomena that take place in such
astrophysical objects like the black-holes are. At present the only possibility how to verify
experimentally these theoretical models on physics of the black-holes is to find a laboratory
system which, obviously with some limitations, mimics some properties of the black holes.
An aim of this lecture is to introduce and present as a theoretical model, so the experimental
results of the experiment made in a limit of absolute zero temperature (600 μK) studying the
spin wave analogue of black/white hole horizon using  a spin (magnonic) superfluidity in
superfluid 3He-B. As an experimental tool simulating the properties of the black/white
horizon we used the spin-precession waves propagating on the background of the spin super-
currents between two Bose-Einstein condensates of magnons in form of the homogeneously
precessing domains. We provide experimental evidence of the white hole formation for spin
precession waves in this system, together with observation of an amplification effect.
Moreover, the estimated temperature of the spontaneous Hawking radiation in this system is
about four orders of magnitude lower than the system's background temperature what makes
it a promising tool to study the effect of spontaneous Hawking radiation.

Speaker: Skyba P. (Centrum fyziky nízkych teplôt, Ústav experimentálnej fyziky, SAV, Košice)

4 QUANTUM WALKS

Quantum walks represent a generalization of the random walk to the coherent evolution of the
quantum particle on a graph or a lattice. We provide an overview of the concept, focusing on
the discrete-time quantum walk, and illustrate the applications in quantum simulations and
quantum computation. Finally, we introduce a very successful experimental implementation
of quantum walks which is based on photonic time-multiplexing, and review the recent
experiments.

Speaker: Štefaňák M. (FJFI ČVUT v Praze)

Stefanak.pdf

12:00 Lunch

Plenary Talks

5 EXPERIMENT KATRIN LIMITED THE NEUTRINO MASS TO LESS THAN 1 eV

Neutrinos are together with photons the most abandon particles in the Universe. The
knowledge of the neutrino mass is important not only for particle physics but also for
cosmology. Oscillation experiments proved that at least two of the known three neutrino mass
states have the mass different from zero, while at least one of these states has the mass greater
than 0.05 eV. Precision spectroscopy of electrons emitted in the nuclear beta decay offers a
principal possibility to determine the neutrino mass directly in a model independent way.
However, only upper limits of the neutrino mass were determined until now. The most
advanced Karlsruhe Tritium Neutrino Mass experiment (KATRIN) operates with a
windowless gaseous source of molecular tritium. The energy of emitted electrons is analyzed
with the electrostatic retarding spectrometer with magnetic adiabatic collimation. Recently,
the first four-week science run of the KATRIN limited the neutrino mass to less than 1.1 eV.
This is twice better that the previous limit achieved after several years of measurement. The
KATRIN aims to the 0.2 neutrino mass sensitivity after 1000 days of measurements. Further
on the hypothetical sterile neutrinos in the eV and keV mass ranges will be searched for.

Speaker: Dragoun O. (Nuclear Physics Institute of the Czech. Acad. Sci., Řež)

Dragoun.pdf

6 CHARACTERIZATION AND BIOAPPLICATION OF MAGNETIC NANOPARTICLES

Magnetic nanoparticles (NPs), especially SPIO nanoparticles, have long been used as MRI
(Magnetic Resonance Imaging) contrast agents and as advantageous nanoplatforms for drug
delivery, taking advantage of their unique magnetic properties and ability to function at the
molecular and cellular level. In our centre smart design and development of SPIO
nanoparticles in mild conditions with desired physico-chemical properties (size, composition,
surface modification, magnetization, relaxivity, biocompatibility, etc.) have been performed
to fulfil desired bioapplication. In this lecture the most promising results will be presented and
consequently discussed advanced in vitro and in vivo MRI application of such prepared SPIO
nanomaterials or nanocomposites. The particular attention will be devoted to labeling and
MRI detection of stem cells, and potential clinical application of maghemite/bentonite
nanocomposite as an per-oral contrast agent.

Speaker: Poláková K. (Regional Centre of Advanced Technologies and Materials, Palacký University in Olomouc)

7 NITRIDE SEMICONDUCTORS - PROPERTIES AND APPLICATIONS

Why are the III-nitride semiconductors so unique that they became the second most important
semiconductor material after silicon? Why it was so difficult to prepare high quality nitride
layers? It was so difficult that scientist, which have partly solved this problem were five years
ago awarded by Nobel Prize. What are the most perspective applications for nitrides? What
problems have to be solved in nitride technology? Answers to these four questions concerning
nitride properties, applications, technology and open problems will be presented in our
contribution. We will show how the piezoelectric field in nitride heterostructures can be
utilized in transistors with high electron mobility, but on the other how it can complicate the
carrier confinement in quantum wells and design of optoelectronic applications. Application
in lasers and light emitting diodes, in high electron mobility transistors (HEMTs) and in
scintillators will be discussed with their advantages and limitations. We will touch also the
most important technological problems and challenges, such as high dislocation density and
possible ways to suppress it, the p-type doping of AlGaN layers, problems with limited
indium atom incorporation. Results of scintillator structure development in our group with the
world record InGaN QW number will be presented.

Speaker: Hospodková A. (Institute of Physics CAS, Prague)

15:25 Coffee break

Plenary Talks

8 Role of photovoltaic solar cells in the ongoing energy systems transformation

Photovoltaic solar energy conversion years has become a decisive part of the
electricity generation. The global installed photovoltaic (PV) capacity surpassed 600 GW in
2020 and the terawatt installed capacity is going to be achieved within the following decade.
The dramatic fall of costs made PV the cheapest source of new electricity generation (without
subsidies) in large part of the world. PV exhibited ~25 % annual growth rate during the last 5
years. PV produces about 3 % of electricity globally, about 5% in the EU and it is expected to
reach 15 % share of EU electricity generation by 2030.
PV is dominated by silicon wafer-based cells for which previously unforeseen low
system prices have been reached. The advantages of photovoltaics based on silicon thin film
(lower consumption of energy-costly silicon and thus shorter energy payback time) have not
been sufficient to overcome the disadvantage of lower efficiencies. Thus the development and
production of silicon thin film photovoltaics nearly stopped. The other types of thin film
based PV (CdTe, CIS) as well as concentrated PV approaches struggle as well.
The record efficiency of silicon based cell reached 26.7 % by using the silicon
heterojunction (SHJ) with interdigitated back contacts composed of intrinsic and either n or p-
type hydrogenated amorphous silicon layers with thicknesses ~ 10 nm. The record SHJ cell
has been fabricated by photolithography, unsuitable for mass production. A simpler stencil
mask based technology has been developed in the NextBase H2020 project. The tunnel-IBC
approach further simplifies the process by eliminating the patterning and aligning the hole
collector contacts. These advances offer a chance for a restart of photovoltaic production in
Europe.
Innovation goes on to further enhance light-to-power conversion efficiency but this is
not possible for single junction silicon based cells, as they are close to the fundamental
Shockley Queisser limit (~29.6 %). Much higher efficiencies are possible with multijunction
designs, but so far they have been demonstrated using III-V semiconductors, which are not
suitable to large scale deployment. The next step in PV evolution will be the dual junction
(tandem) cells of silicon with a suitable partner. The most perspective is the combination of
perovskite – silicon tandem cells, with potential efficiency above 45% and current research
results reaching 29%.

Speaker: Fejfar A. (Institute of Physics, Czech Academy of Sciences, Prague)

9 ORGANIC SEMICONDUCTORS

Organic semiconductors are a broad family of organic molecular materials that exhibit certain
properties similar to inorganic semiconductors. Interestingly, molecular materials show only
weak forces between the molecules which gives an opportunity of new deposition methods.
The low-temperature evaporation in a vacuum is applicable for various small molecules,
whereas “wet technologies” using organic material solubility in solvents are famous of large
molecules and polymers. The thin-film fabrication technology is not only unique property of
these materials; organic semiconductors exhibit semiconducting properties even without any
doping. Hence, the organic semiconductors do not represent only alternative semiconducting
materials, but it is also an exciting challenge for electronics and device physics. It has been
found that the semiconducting properties have different microscopic origin than the inorganic
materials even though the macroscopic behaviour is sometimes almost identical. Interestingly,
in contrast with very first ideas researcher commented that “organic semiconductors” can be
misleading term and suggests to call these materials “organic semi-insulators” but it is too late
for such a correction. Actually, it is fascinating to state “Yes, it works, but we are still not sure
why”.

Speaker: Weis M.

10 TIME‐RESOLVED OPTICAL AND TERAHERTZ STUDIES OF THIN‐FILM FERROMAGNETS AND ANTIFERROMAGNETS

Recent breakthroughs in electrical detection and manipulation of antiferromagnets have
opened a new avenue in the research of non-volatile spintronic devices. Antiparallel spins in
antiferromagnets lead to the insensitivity to magnetic field perturbations, multi-level stability
and ultra-fast spin dynamics, which is also a major experimental challenge [1]. In this
contribution we show how the know-how that we achieved in the pump-probe study of spin
transport in non-magnetic heterostructures AlGaAs/GaAs [2], diluted ferromagnetic
semiconductor (Ga,Mn)As [3] or terahertz magneto-resistance [4] can be transferred to the
research of antiferromagnetic metal CuMnAs. In particular, we show the latest progress in
studies of magnetic anisotropy [5], dynamics of heat dissipation [6] and even switching of
memory devices by single femtosecond laser pulse [7] or terahertz excitation [8].
[1] P. Němec et al., Nature Physics 14, 229 (2018)
[2] L. Nádvorník et al., Scientific Reports 6, 22901 (2016).
[3] P. Němec et al., Nature Physics 8, 411 (2012)
[4] L. Nádvorník et al., submitted to Nature Communications.
[5] V. Saidl, et al., Nature Photonics 11, 91 (2017)
[6] M. Surýnek et al., J. Appl. Phys. 127, 233904 (2020)
[7] Z. Kašpar et al., arXiv 1909.09071
[8] J. Heitz et al., submitted to Nano Letters.

Speaker: Nádvorník L. (Faculty of Mathematics and Physics, Charles University, Prague)

11 Welcome party

Tuesday 8 September

Plenary Talks

12 ELECTROMAGNETIC STRUCTURE OF MESONS AND BARYONS

Present state of elementary particles to be specified by a set of quantum numbers is
summarized. An existence of four types of interactions between elementary particles is
reminded with an emphasis that not all particles are able of all four interactions. Those to be
able of strong interactions are named “hadrons”- compound of “quarks”. Compound from
quark-antiquark are “mesons” and compound from three quarks are baryons. Recently four,
even five quarks hadrons are confirmed experimentally, not to be in contradiction with QCD.
Nevertheless X,Y,Z particles are out of any classification into multiplets to be known for
standard mesons and baryons. Hadrons in interaction with charged leptons manifest space
structure to be called electromagnetic (EM) structure, first time revealed for protons before
the quark model of hadrons was established. It is described by “EM form factors (FFs)” the
number of which depends on spin of hadron. The Unitary and Analytic model of FFs is
presented to be based on analyticity and existence of vector-meson-resonances with quantum
numbers of photon. Model depends on some unknown coupling constant ratios. Therefore it is
applicable only to hadrons for which some experimental data exist. As a result only the EM
structure of the nonet of pseudoscalar mesons and the ½^+ octet baryons is completely
described in the framework of this model up to now.

Speaker: Dubnička S (Institute of Physics, Slovak Academy of Sciences, Bratislava)

13 SELECTED RESULTS OF THE ATLAS EXPERIMENT WITH SIGNIFICANT CONTRIBUTION OF CZECH AND SLOVAK PHYSICISTS

The ATLAS experiment is the largest particle physics detector installed at the Large Hadron
Collider at CERN, which measures the proton-proton (or lead-lead) collisions at the world-
highest energies. The precision measurements of the physics processes and particles'
properties probe our current theory of elementary particles, the so-called Standard Model
(SM). The discovery of the Higgs boson in 2012 opened a new territory to be explored - its
detailed properties and interactions. Another exciting goal for now and the future is the search
for new physics phenomena behind the SM.
The ATLAS Collaboration produces plenty of physics results every year. This talk
concentrates on recent analyses with significant contribution of Czech and Slovak physicist
participating in this experiment, for instance the measurement of selected Higgs boson
decays, top-quark physics, rare decays of B-mesons and heavy-ion physics.

Speaker: Tomas Davidek (Charles University (CZ))

atlas_cz_sk_new.pdf

09:50 Coffee break

Plenary Talks

14 Explosions in the Universe and the Origin of Chemical Elements

Recent detection of gravitational waves from merging black holes and neutron stars opened a
new window for studying the Universe and further accelerated the tremendous progress in
multiwavelength time-domain astronomy. This talk will review exciting new developments in
the quest for uncovering the origin of chemical elements in the Universe and understanding
the birth of neutron stars and black holes. These major unsolved astrophysical problems are
associated with some of the most luminous explosions and involve a wide range of physics
such as nuclear matter at high densities, neutrinos, strong magnetic fields, and formation of
dust and molecules.

Speaker: Pejcha O. (Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles university)

15 TEN YEARS OF COMPASS TOKAMAK OPERATION

The COMPASS tokamak, originally constructed and operated at UKAEA in UK, has been
reinstalled at the Institute of Plasma Physics of the CAS in 2009 and experienced a fruitful
decade of scientific exploration. In this contribution, we will summarize the main
achievements, which have contributed to the physics understanding of tokamak plasmas and
development of nuclear fusion related technologies. These include: (i) investigation of the
power decay lengths in limited plasmas, which directly impacted the design of the ITER inner
wall plasma-facing components, (ii) error field (EF) experiments using the unique set of the
tokamak high-field-side error field coils, (iii) power exhaust studies, (iv) runaway electron
characterization and mitigation programme, and others.
COMPASS tokamak will be shut down before the end of 2020 to make space for a completely
new machine: COMPASS Upgrade. Characteristics of this challenging device will be
presented.

Speaker: Komm M. (Institute of Plasma Physics of the CAS, Prague)

16 Czech participation in new European Large Research Infrastructure FAIR

Czech Republic is aspirant member of the Facility for Antiproton and Ion Research (FAIR)
since March 2019. Unique new European Large Research Infrastructure FAIR is currently
built up at the campus of German national laboratory for heavy ion research GSI Darmstadt.
It will cover research in nuclear and hadron physics as well as in associated fields. It is
included in the European Strategy Forum on Research Infrastructures (ESFRI). The current
status of FAIR construction will be discussed as well as current status and future enlargement
of Czech participation in all four pillars of FAIR, i.e. in CBM, NuSTAR, PANDA a APPA.
Now days Czech scientist from NPI CAS, Silesian University at Opava and Czech Technical
University are involved in studies of compressed baryonic matter (HADES, CBM); team from
Silesian University is involved in studies related to nuclear astrophysics (NuSTAR); teams
from Charles University and Czech Technical University participate in R&D and construction
of detectors for PANDA pillar devoted to particle physics. APPA pillar is devoted to
application of nuclear and hadronic physics in further fields, like plasma physics,
radiobiology, testing of detectors for European Space Agency (ESA) etc. Small group from
NPI CAS interested in radiobiology participates now in APPA, further Czech groups involved
in other fields covered by APPA as well as by other pillars, are welcomed. Investments of
Czech groups in experiments planned to be carried out in FAIR are currently covered mainly
by Large Research Infrastructure FAIR-CZ.

Speaker: Kugler A. (NPI CAS, Řež)

Kugler.pdf

12:00 Lunch

17 Registration for teachers

Registrace učitelů

Parallel sessions: didaktika fyziky

18 TRENDY VO FYZIKÁLNOM VZDELÁVANÍ, OČAKÁVANIA A REALIZÁCIA

Abstrakt: Vzdelávanie je procesom sprístupňovania nadobudnutých poznatkov a overených
postupov z vybranej oblasti ľudskej činnosti, ponúkajúcim využívanie a nadväznosť na
existujúcu úroveň vedy, techniky či spoločenských zvyklostí. Kvalitným vzdelávaním nie iba
informujeme o minulosti, ale najmä iniciujeme smerom k budúcnosti. Fyzika, ako veda, má
obrovský vzdelávací potenciál z pohľadu rozvoja vedeckej gramotnosti, štúdia novodobých
vedeckých tém, prepájania základného a aplikovaného výskumu, interdisciplinarity a silnej
väzby na informatiku. Fyzika, ako vyučovací predmet, je unikátnym priestorom pre aktívne
poznávanie, bádateľskú výučbu, formatívne hodnotenie, kolaboratívne učenie, rozvoj
zručností a spôsobilostí, vyšších poznávacích procesov. Náročnosť sprístupňovania
vzdelávacieho obsahu vo fyzike si vyžaduje spoluprácu vedcov, didaktikov a učiteľov
v oblastiach tvorby kurikula, aplikácie vyučovacích metód, popularizácie a neformálneho
vzdelávania. Vysoké očakávania z pohľadu profilu absolventa, kladú požiadavky na
vzdelávanie, ktoré položí silné základy pre neustálu adaptáciu, inováciu, kreativitu, či riešenie
globálnych výziev, o ktorých dnes iba uvažujeme. Vďaka národným a medzinárodným
projektom sa už dnes realizujú vzdelávacie koncepty, ktoré veríme, že naplnia naše
očakávania. Koncept gymnaziálnych tried so zameraním na informatiku, prírodné vedy
a matematiku, ako jeden z produktov národného projektu IT Akadémia, je v príspevku
predstavený s dôrazom na inováciu obsahu a metód fyzikálneho vzdelávania, profiláciu
absolventa, jeho orientáciu a pripravenosť na vysokoškolské štúdium STEM odborov.

Speaker: Kireš M. (Ústav fyzikálnych vied Prírodovedecká fakulta UPJŠ v Košiciach)

19 ŠKOLSKÝ MERACÍ SYSTÉM S VYUŽITÍM MIKROKONTROLÉRA

Zvyšovanie výpočtového výkonu počítačových komponentov, ktoré je sprevádzané
znižovaním ich cien je predpokladom vzniku nových progresívnych oblastí, ktoré postupne
získavajú na popularite, vďaka čomu získavajú masový rozmer. Tieto nové technológie rýchlo
prenikajú do rôznych oblastí nášho života a školstvo nie je výnimkou. V čase, keď väčšina
žiakov vlastní digitálne zariadenie sa využitie týchto zariadení aj na vzdelávacie účely javí
ako dobré riešenie. Predpokladom takéhoto riešenia je existencia systému, ktoré umožňuje
okrem plnenia edukačných úloh aj zabezpečovať komunikáciu so zariadeniami učiteľov a
študentov. Školský elektronický merací systém predstavuje technický prostriedok pre
realizáciu merania, ktorý následne poskytuje namerané údaje užívateľovi pre ich ďalšie
spracovanie. Elektronické meracie systémy predstavujú zaujímavý nástroj pre zefektívnenie
výučby fyziky na základných a stredných školách. V príspevku autori predstavujú vlastný
vyvinutý školský merací systém základom ktorého je mikrokontrolér ESP32. Veľkou
výhodou systému je jeho univerzálnosť a škálovateľnosť, vďaka čomu môže systém plniť aj
špecifické požiadavky užívateľa. Modulárnosť systému zase zjednodušuje prácu s
jednotlivými komponentmi a sprehľadňuje jeho štruktúru aj pri jeho pomerne vysokej
komplexnosti. Vďaka bezdrôtovej technológii a použitiu kompatibilných komunikačných
protokolov je možné sa k systému pripájať pomocou zariadení bez ohľadu na ich operačný
systém. Súčasťou návrhu systému je aj návrh plošného spoja elektroniky a zapuzdrenia
komponentov.

Speaker: Choma M. (Faculty of Humanities and Natural Sciences, Prešov University, Prešov)

20 MODELOVANIE ZMENY TIAŽOVÉHO ZRÝCHLENIA A JEHO VPLYVU NA TLAK V KVAPALINE

Cieľom príspevku je ponúknuť učiteľom fyziky spôsob ako rozvinúť žiacke predstavy
o tlaku v kvapalinách, o jeho príčine a dôsledkoch. Zaoberáme sa preto chápaním pojmov
tiaž, tiažová sila, gravitačná sila. Venujeme sa tiež pokusu s kvapalinou v beztiažovom stave,
kedy na telesá ponorené v kvapaline nepôsobí vztlaková sila. V príspevku navrhujeme
experiment zameraný na overenie lineárnej závislosti tlaku v kvapaline od tiažového
zrýchlenia. Zmenu tiažového zrýchlenia modelujeme využitím princípu Atwoodovho
pádostroja. Experiment odporúčame realizovať so žiakmi vyšších ročníkov strených škôl
a gymnázií.

Speaker: Kováč M. (Fakulta didaktiky matematiky, fyziky a informatiky, Univerzita Komenského v Bratislave)

21 Faktory ovlivňující vnímání demonstračních experimentů studenty: Videostudie

Experiment je základním prvkem nejen ve fyzice jako vědě, ale také ve výuce fyziky. Ačkoliv
je v poslední době více výzkumné pozornosti věnováno samostatnému experimentování žáků
v rámci badatelské výuky, významnou roli stále ve školách hraje demonstrační experiment.
Na katedře didaktiky fyziky MFF UK má projekt předvádění demonstračních experimentů pro
studenty středních škol tradici více než 30 let a v současné době nabízí celkem sedm
tematických celků.
Výzkum provedený ve školním roce 2017/18 na vzorku cca 5100 studentů však ukázal, že
tyto tematické celky jsou studenty vnímány poměrně odlišně zejména z hlediska jejich zájmu,
vnitřní motivace a subjektivně vnímané užitečnosti a hodnoty. Nabízí se tedy otázka, zda
existují parametry, které předurčují pozitivní vnímání demonstračních pokusů studenty – ať
už by mělo jít o požadavky na performera, o způsob práce s publikem či o výběr jednotlivých
experimentů.
Cílem tohoto příspěvku je představit výsledky videostudie, které byly podrobeny
videozáznamy všech sedmi tematicky odlišných vystoupení, a interpretovat tyto výsledky ve
spojení s tím, jak pozitivně či negativně studenti daná vystoupení vnímali.

Speaker: Kácovský P. (Katedra didaktiky fyziky MFF UK, Praha, Česká republika)

Parallel sessions: jaderná a částicová fyzika

22 Nuclear Methods for Astrophysical Purposes

It is widely known that nucleosynthesis takes place into stars. Element lighter than
Iron and heavier than Lithium (partially produced in primordial nucleosynthesis) are
in fact produced during stellar evolution by means of the interaction between
charged and neutral particles. About charged particles its interactions is strongly
hampered by the presence of the Coulomb barrier – usually around some MeV – that
is much higher than the typical energies of thermal agitation of particles inside a star
(between tenth and thousands of keV). This fact generates the strong, exponential
fall of the cross-section that can be observed in many experiments that have been
conducted through the years. This often makes really hard – when not virtually
impossible – the study of this reactions in our laboratories around the world.
Regarding the reactions involving neutrons in the entrance channel, experiments are
complicated by the many difficulties involved in produce a suitable neutron beam. To
overcome these problems many indirect methods have been developed through the
last decades, and in particular the Asymptotic Normalization Coefficient (ANC)
method and the Trojan Horse Method (THM) have proven to be quite useful to study
reactions involving charged particles and neutrons in the entrance channel.

Speaker: D’Agata G.F. (Nuclear Physics Institute of the Czech Academy of Sciences, Řež)

DAgata.pdf

DAgata.pptx

23 THE PROTON AND DEUTERON ACTIVATION AT NPI CAS AND SPIRAL2/NFS FRANCE

Knowledge of experimental activation cross sections is important for creation and evaluation
of evaluated libraries (TENDL) used by various programs for design accelerators, their
components, reactors, but also for nuclear structure study. The proton and deuteron activation
cross sections have been studied at NPI CAS (Nuclear Physics Institute) for many years at
variable energy cyclotron U120M. Deuteron energy is limited to 20 MeV. For this reason we
took advantage of the opportunity to extend this research to the new facility SPIRAL2/NFS
(Neutrons For Science) constructed at GANIL/SPIRAL2 in France. Charge-particle
irradiation chamber was developed and constructed at NPI CAS. The chamber is equipped
with a pneumatic transfer system that allows measurement of activated isotopes with halflives
in minute region. The first test with protons was made at the end of 2019.
The proton induced reaction cross sections on iron were investigated by stacked-foil
activation technique with initial proton beam of energy 20 MeV from the cyclotron U-120M
of the NPI CAS, Řež and the measurements confirmed the data of previous authors. We
determined production cross sections for 58m Co a 58g Co for the first time. We also determined
the production cross sections for 51 Mn which were incorrectly ascribed to 51 Cr. The
investigation will continue for higher proton energy interval up to 33 MeV at SPIRAL2/ NFS
with the equipment allowing measurement of products with halflives in minute region (e.g.
54m Co, 53m Fe) and using isotopically enriched targets.

Speaker: Šimečková E. (NPI CAS, Řež)

Simeckova.pdf

Simeckova.pptx

24 DETECTION FOR (N,G*) REACTIONS BY FAST NEUTRONS

Precise nuclear data are of great importance in the design of fusion and ADS devices. The
studies of prompt and delayed gamma rays from (n,g*) reactions bring important knowledge
as it is one of the main sources of nuclear data such as cross-section, nuclear energy levels,
etc.
A central part of the capability is the Cyclotron U-120 and neutron converter coupled to the
collimator. The collimated neutron beam of fast neutrons (with energies up to 33 MeV) was
recently acquired at the Laboratory of Fast Neutrons of the NPI CAS. The detection system
for the prompt gammas irradiated in the reaction of studied material with fast neutrons is
being constructed. The setup consists of an array of HpGe detectors. The first experiments
performed have shown that the setup was able to detect delayed gammas with decay times of
a few ms. Future tests will focus on detecting prompt gammas.

Speaker: Koliadko D. (Nuclear Physics Institute of the Czech Academy of Sciences, Řež)

25 NUCLEAR DATA MEASUREMENTS WITH COLLIMATED FAST NEUTRON BEAMS PRODUCED BY CYCLOTRON-DRIVEN NEUTRON GENERATORS

At the Nuclear Physics Institute at the laboratory of Fast Neutron Generators, a new neutron
collimator was recently constructed. Simultaneously a new neutron converter coupled to the
collimator was constructed and successfully tested last year. Collimated beams of fast
neutrons bringing new experimental possibilities especially for on-beam measurements with
semiconductor detectors. Motivated by the development of future fission and fusion energy
projects the nuclear data measurements of cross-sections for nuclear reactions induced by fast
neutrons are under preparation (or were already conducted) at the Department of Nuclear
Reactions at the NPI CAS. A new vacuum chamber with silicon detector composed telescopes
will allow us to perform precise measurements of double-differential cross-sections for
interaction (n, cp) induced by fast neutrons with kinetic energies from 5 to 33 MeV. The
current status of development and preparations for experiments with the new vacuum
chamber will be given.
Moreover already measured experimental total cross-section data for reaction nat O(n,tot) will
be shown and a particular experimental approach to transmission experiments will be
described.

Speaker: Ansorge M. (Nuclear Physics Institute of the Czech Academy of, Řež)

Ansorge.pdf

Ansorge.pptx

26 EFFECTS OF HIGH PRESSURE ON THE RADIOACTIVE DECAY

It is well known that the radioctive decay can be influenced from external environment [1][2].
However we still don't have a univocal picture that describes these effects. Understanding
how the radioctive decay is influenced in high density environments is useful for different
fields like, for example, the relevant fusion processes in stellar environment [3] or for isotope-
cycling and fractionation on Earth [4]. Therefore we prepare a test at the Nuclear Physics
Institute of the Czech Academy of Science. We will use three large HPGe detectors to
measure gamma-rates from a solid target of 22 Na under high pressure. The source of 22 Na
decays by β + that presents a strong gamma line, it has reasonably long half-life (T 1/2 = 2.6 yr)
and it is commercially avaible. This simple system may provide an optimal test-bench.
Hereby we will present and discuss our preparations for the test.
REFERENCES
[1] H. Mazaki, et. al - PHYSICAL REVIEW C VOLUME 5, NUMBER 5 MAY 1972
[2] N. Nissim et. al - PHYSICAL REVIEW C 94, 014601 - (2016)
[3] C. Nociforo et al. - Phys. Scr. T 150, 014028 (2012)
[4] M.B. Andersen, et. al - Nature 517, 356 (2015)

Speaker: Cassisa A. (Nuclear Physics Institute of the Czech Academy of Sciences, Řež)

15:10 Coffee break

Parallel sessions: didaktika fyziky a terminologie

27 FYZIKA PRO NEJMENŠÍ A JEJICH UČITELE

Co zajímá nejmenší "fyziky" z mateřských škol a prvního stupně základních škol, co se jim
líbí a co všechno dokáží, a co na to jejich učitelé? Co vše lze prostřednictvím jednoduchých
fyzikálních pokusů u dětí rozvíjet? Jak fyzika pomáhá spolupráci učitelů z různých typů škol?
Při odpovídání na předchozí otázky vychází autorka ze své mnohaleté zkušenosti se
zprostředkováváním fyziky předškolním a mladším školním dětem a jejich učitelům v rámci
vlastního autorského programu Pohádková fyzika i v rámci Elixíru do škol.

Speaker: Houfková J. (Katedra didaktiky fyziky MFF UK, Praha)

28 SMÍCHOVSKÁ PRŮMYSLOVKA TŘETÍHO VĚKU

Smíchovská střední průmyslová škola se dlouhodobě snaží o zavádění nových forem výuky,
se kterými souvisí také snaha o status otevřené instituce přístupné všem generacím. Centrem
všeho dění jsou samozřejmě studenti školy, kteří mají možnost se všeobecně rozvíjet, a to
nejen klasicky v hodinách, ale i jako asistenti či vedoucí workshopů pro mateřské a základní
školy a od roku 2015 také pro seniory. Smíchovská průmyslovka třetího věku je dlouhodobý
projekt podpořen grantem magistrátu hl. města Praha, který formou pravidelných přednášek a
workshopů pomáhá k rozvíjení technických schopností seniorů ale i sociálních vazeb mezi
mladou generací a seniory.

Speaker: Krajčová V. (Smíchovská střední průmyslová škola, Praha)

Krajcova.pdf

Krajcova.pptx

29 CANCELED!!! STRASTI A SLASTI UČITEĽA FYZIKY V ROKU 2020

Vyučovací proces, nielen predmetu fyzika, má svoje viac či menej zaužívané pravidlá.
Zvyčajne sa ich adepti na učiteľstvo dozvedajú na pri štúdiu na vysokej škole. V tomto
príspevku chceme odpovedať na niekoľko otázok a podať informácie, ktoré sa možno pri
štúdiu nedozvedia. Napríklad:
Je vyučovanie fyziky iné oproti iným predmetom? Ako sa mení úloha učiteľa fyziky
v posledných rokoch? Sú vytvorené podmienky na kvalitné vyučovanie fyziky na základných
a stredných školách? Ako môže vyzerať „dobrá“ vyučovacia hodina fyziky? Čo sa zmenilo na
metodickej pomoci organizácii nazvanej Metodicko-pedagogické centrum v posledných
desaťročiach? Kde sú IT technológie rozumné využiteľné a kde ich pomoc je skôr prekážkou?
Je 3D tlač pre obyčajného učiteľa fyziky prínosom? Boli sme pripravení na online vyučovanie
fyziky a zvládli sme ho?

CANCELED

Speaker: Beňuška J.

30 Kulatý stůl k otázkám české terminologie ve fyzice (má ještě smysl psát o fyzice česky?)

Speaker: Valenta J.

Parallel sessions: fyzika pevných látek

31 STRUCTURAL AND MAGNETIC PHASE DIAGRAMS OF RMn 1-x Fe x O 3 SYSTEM WITH PEROVSKITE CRYSTAL STRUCTURE

The transition metal oxides, with perovskite structure, have been largely studied because these
materials exhibit strong coupling between orbital, electronic, spin and lattice degrees of
freedom. The atomic substitution at the dodecahedral sites in stoichiometric compounds has
been extensively studied and recently, interest has turned on to the effect of the substitution at
the octahedral sites, where the experimental studies have been mainly focused on the
magnetic behaviour, and few on the multiferroic properties. In our paper we focus on
construction of structural and magnetic phase diagrams of RMn 1-x Fe x O 3 system with
perovskite crystal structure (R = Nd, Pr, Tb and Dy). Our study was performed on single
crystals prepared by optical floating zone method. We studied creation of the substitutional
solid solutions in whole concentration range, evolution of Jahn-Teller (JT) effect and orbital
ordering with substitution at the octahedral sites with non-active JT ion Fe 3+ . Construction of
magnetic phase diagrams was undertaken with particular emphasis to determination of
magnetic structure by means of magnetization, heat capacity and neutron diffraction
measurements. We paid special attention to tuning of magneto-electric (ME) coupling in
multiferroic compounds (RMnO3, R = Tb, Dy) with magnetically induced ferroelectricity by
low concentration doping with Fe.

Speaker: Mihalik M. (Institute of Experimental Physics, Slovak Academy of Sciences, Košice)

32 EXPERIMENTAL STUDY OF EMERGENT GROUND STATE BEHAVIOUR IN RENi 5 (RE = Ce, Yb, Gd) SYSTEM

The study of intermetallic compounds has a long history. Rare earth intermetallic
compounds are systematically investigated more than 3 decades already. Polycrystalline
samples (Ce,Gd,Yb)Ni 5 were prepared by different ways, where interesting physical problems
were studied.
In this work we focused on competition between the effect of spin fluctuations and the
possible existence of quantum criticality, a dimension response of physical properties and the
response of chemical pressure on the physical properties.
First of all, structural analysis confirms required crystal structure and scanning
electron microscopy shows the chemical compositions. After that, magnetic and thermal
properties were performed by using several experimental techniques. The results will be
displayed.
Collected experimental data show, that substitution of rare earth atoms in a compound
has very important role. An interesting physical property can be observed due to acquired
information.

Speaker: Džubinská (CPM-TIP, UPJS, 040 11 Košice)

33 THE SEARCH FOR MULTIFERROELECTRICITY: THE CASE OF NICKEL TELLURIDES

Multiferroic materials exhibiting coupled magnetic and electric orderings are intensely
studied due to an interest in both their fundamental properties and potential applications based
on the magnetoelectric coupling. In general, magnons are collective spin excitations of
various types. In multiferroics, the electric component of the electromagnetic radiation can
excite magnons via the dynamic magnetoelectric coupling. These excitations are then called
electromagnons; they can be difficult to distinguish from classical magnons. One possible
method consists in comparing terahertz or infrared spectra with Raman spectra. In fact, the
electromagnons, unlike magnons, must follow the same selection rules as polar
phonons—they must be active in both kinds of spectra.
In this presentation, we will illustrate our approach by the study of nickel tellurides [1,2,3].
Indeed, a colossal magnetoelectric coupling has been found in Ni 3 TeO 6 . For the first time, we
managed to synthetise its isostructural compounds by substitution of Ni with Mn or Co. Low-
temperature spectra revealed electromagnons sensitive to magnetic field, which proves the
multiferroic character of the compounds.

Speaker: Kadlec Ch. (1 Institute of Physics, Czech Academy of Sciences, Na Slovance 2, Prague)

34 FRUSTRATED SHASTRY-SUTHERLAND METALLIC SYSTEMS TMB 4 AND ERB 4

Geometrically frustrated lattices play an important role in emergent quantum mechanical
phases, which have been rather well investigated in electronic insulators. A system that
exhibits both lattice frustration and metallic behaviour are the rare-earth (RE) tetraborides
REB 4 . They have a tetragonal structure with magnetic RE ions embedded in boron network
and forming a lattice topologically equivalent to the frustrated Shastry-Sutherland lattice with
the strong Ising single-ion anisotropy.
In our contribution we compare the behaviour of TmB 4 and ErB 4 by investigating the angular
dependencies of their thermal and magnetic properties in a wide range of temperatures (T) and
magnetic fields (H) as well as transport properties under pressure up to 3 GPa. Compared are
also the rotating magneto-caloric effects (R-MCE) of both compounds. Spin-electron model
was suggested to explain the complex behaviour of R-MCE, which is based on the idea of two
interacting systems: the localized spins of RE ions and the itinerant electrons in conduction
band. The received results from Monte Carlo approach successfully reproduce the observed
heating and cooling regions in H - T phase diagrams of TmB 4 . Thus, our study shows that
measurements of R-MCE can be an effective tool for investigating the microscopic properties
of magnetization processes.

Speaker: Gabáni S. (Institute of Experimental Physics SAS, Košice)

35 SKÚMANIE MIKROŠTRUKTÚRY OCELÍ POMOCOU MÖSSBAUEROVEJ SPEKTROMETRIE

Mikroštruktúra materiálov determinuje aj ich makroskopické fyzikálne vlastnosti. Tie je
nevyhnutné poznať hlavne v prípade ocelí, ktoré sa používajú ako základný materiál pre
konštrukčné prvky jadrových zariadení. Ukazuje sa, že chróm v rôznych zliatinách má
antikorózne vlastnosti kvôli povrchovej segregácii a tvorbe pasivačnej vrstvy. Práve preto sú
ocele s prímesou chrómu vhodným kandidátom pre tlakové nádoby jadrových reaktorov.
Pre výskum mikroštruktúry ocelí je mimoriadne vhodná Mössbauerova spektroskopia, ktorá
pomocou hyperjemných interakcií medzi jadrami 57 Fe a príslušným elektrónovým obalom
citlivo popisuje ich lokálne usporiadanie. Poskytuje informáciu o štruktúrnom usporiadaní
(typ kryštalických fáz) a aj magnetickom stave. V prezentácii budú diskutované rôzne
spôsoby vyhodnocovania Mössbauerových spektier modelových zliatin typu Fe-Cr s obsahom
Cr v rozsahu 1-50 at. %. Pre nízke koncentrácie Cr (do 15 at. %) je vhodná metóda
binomického rozdelenia, u vyšších zas distribúcie hyperjemných magnetických polí. Zloženie
modelových vzoriek bolo overené metódou röntgenovskej fluorescencie, ich povrch bol
skúmaný pomocou rastrovacej elektrónovej mikroskopie. Získané výsledky budú použité pri
skúmaní mikroštruktúry reálnych typov konštrukčných ocelí.
Práca bola podporená projektom VEGA 1/0130/20.

Speaker: Košovský D. (Ústav jadrového a fyzikálneho inžinierstva, Slovenská technická univerzita v Bratislave)

36 Current development in the study of magnetically induced crystal reorientation of Ni-Mn-Ga ferromagnetic shape memory alloy

In the past two decades Ni-Mn-Ga Heusler alloys have received great attention as these
exhibit magnetic shape memory effects, first described in 1999. Modulated Ni 2 MnGa
martensite has exceptionally low stress for pseudoplastic deformation or structural
reorientation by twinning mediated by highly mobile twinning boundaries [1]. Owing to large
magnetic anisotropy and low twinning stress the large pseudoplastic deformation can be
induced by a magnetic field. Thus, these materials can replace giant magnetostrictive
materials with fast external actuation control and strain exceeding 10 % [1].
In this study, the energy needed for the deformation by a magnetic field and by mechanical
force was measured and compared in monocrystalline Ni 50 Mn 28 Ga 22 modulated martensite. 
Measurements were conducted on five samples by vibration sample magnetometer and stress-
strain device to compare directly different modes of loading. In contrast with the
phenomenological model [2] the calculated energy of magnetically induced reorientation or
pseudoplastic deformation were considerably higher compared to the energy needed using
mechanical force. The switching field of samples with nucleated twinning boundaries was
also measured and compared to single variant crystals. Results only partly support modelling
of the twinning stress and switching field [1-3]. The model-data discrepancies are an
unresolved issue suggesting a need for modification of the model.

Speaker: Heczko O. (Department of Magnetic Measurements and Materials, Institute of Physics CAS, Prague)

17:55 Quick dinner

Programme open to general public

37 kulatý stůl "Jak učíme fyziku - postřehy a nápady"

38 TAJOMSTVÁ FUJARY A PÍŠŤALIEK

Píšťalky a najmä fujara sú neodmysliteľnou súčasťou slovenskej kultúry a svetového
kultúrneho dedičstva. Najviac osobitými slovenskými píšťalami sú fujara (najdlhší nástroj
tohto typu na svete) a koncovka (píšťala bez dierok). Fujara si získala celosvetovú pozornosť
najmä špecifickou farbou zvuku, koncovka zasa svojou jednoduchou konštrukciou
a spôsobom hry na ňu. Oba tieto nástroje však môžu slúžiť aj ako učebné pomôcky pri výučbe
viacerých oblastí fyziky, napríklad šírenie zvuku a stojace vlny, hydrodynamika tekutín, alebo
základy harmónie z pohľadu frekvencie zvuku.
Na koncovke a fujare možno pekne ilustrovať (počuť) rôzne typy stojacich vĺn (vyššie
harmonické kmitočty) za okrajovej podmienky ako otvoreného, tak aj uzavretého konca.
Vybudením vyšších harmonických kmitočtov sa dajú vysvetliť tradičné hudobné ozdoby
hráčov na fujaru, ako sú rozfuk a prefuk. Prúdenie plynu za vzniku vírov je kľúčovým
faktorom pri vzniku kladnej spätnej väzby a trvalého tónu. Pytagorejská teória harmónie spolu
so štruktúrou vyšších harmonických tónov generovaných v píšťale umožňuje vysvetliť spôsob
hry na koncovku a tiež to, prečo minimálny počet dierok na píšťale sú tri (ako má aj fujara)
a prečo majú píšťaly najčastejšie 6 dierok.
Ukážky rôznych (aj primitívnych) nástrojov a hry na ne môže spestriť výučbu fyziky a tiež
zvýrazniť väzbu fyziky na iné odbory.

Speaker: Kundracik F. (Katedra experimentálnej fyziky, Fakulta matematiky, fyziky a informatiky, Univerzita Komenského v Bratislave)

39 VODÍK – PALIVO PRO UDRŽITELNOU ENERGETIKU

Odklon od využívání fosilních paliv vyžaduje hledání nových nosičů energie, které budou
nezbytné pro dosažení ambiciózního cíle uhlíkově neutrální energetiky. Přestože podíl výroby
elektrické energie z obnovitelných zdrojů, především solární a větrné, neustále roste,
významnější závislost na těchto zdrojích bude spojena s řešením různých problémů,
spojených především s vlivy počasí a geografického umístění na jejich efektivitu. Obtížná
regulace produkce elektrické energie z obnovitelných zdrojů vyžaduje hledání způsobu
reverzibilního ukládání energie a nových chemických nosičů energie. Zatím se jako
nejperspektivnější jeví využití vodíku, a je zřejmé, že vodík bude důležitou součástí
energetického mixu budoucnosti. Pokles ceny solární a větrné energie vede k rozvoji výroby
„čistého“ vodíku elektrolýzou vody a umožňuje tak ukládání přebytků energie. Energii
z vodíku lze zpětně přeměnit ve vodíkovém cyklu na energii elektrickou v palivových
článcích, které mohou být jak stacionární, tak mobilní. Mobilní prostředky jsou v podstatě
elektrické hybridní systémy, kde je baterie doplněna vodíkovou nabíječkou. Vodík se
uplatňuje v manipulační technice, bude využit v elektrickém letectví, kamionové a lodní
dopravě. Vodík jako nosič energie má výhodu rychlého čerpání a rovněž delšího dojezdu.
Vodíková budoucnost je neoddělitelně spojena s využitím baterií a hybridní systémy budou
tím víc nezbytné, čím větší spotřebu bude mít dané zařízení.

Speaker: Matolín V. (Matematicko-fyzikální fakulta, Univerzita Karlova, Praha)

Wednesday 9 September

40 Slavnostní předání cen Milana Odehnala, zvaná přednáška vítěze

41 Valná hromada Slovenské fyzikální společnosti CANCELED!!

Canceled

10:00 Coffee break

Parallel sessions: didaktika fyziky a biomechanika

42 STUDENTS’ SOLVING OF MULTIPLE-CHOICE TASKS FOCUSED ON GRAPH SLOPE INTERPRETATION OBSERVED BY THE EYE-TRACKING METHOD

We employed the eye-tracking method (Eyetracker by Tobii, 300 Hz) in order to observe
students’ strategies of choosing an option when they solved multiple-choice tasks focused on
graph slope interpretation. Each student solved 7 multiple-choice tasks focused on graphs in
kinematics. Most tasks were adopted from Beichner’s TUG-K test (Beichner, 1994).
Particularly, they were focused on position-time graphs and determining velocity from the
graphs as it is stated in the Objective 1 of the Beichner’s original test. Altogether 23 high
school students participated in the study (8 women, 15 men). Each stem-text, stem-graph and
each option was marked as a separate Area Of Interest for every task.We provide comparison
of attention allocation between two students group: those, who solved a test task correctly and
those who not. Based on the data analysis, we observed and described different students
understanding of the graph slope concept. Moreover, we applied the cluster analysis in order
to divide students into groups according to their attention spent on each option. We obtained
very similar results as in the previous case.
Beichner, R. J. (1994). Testing student interpretation of kinematics graphs. American Journal of
Physics, 62, 750–762.

Speaker: Kekule M. (Katedra didaktiky fyziky, MFF UK, Praha)

43 DOPLŇKOVÉ KURZY (BRIDGING COURSES) PRO STUDENTY 1. ROČNÍKŮ NA VYSOKÝCH ŠKOLÁCH

Cílem příspěvku je prezentovat výsledky mezinárodního šetření o existenci a obsahu
překlenovacích kurzů pro absolventy středních škol, kteří nastupují do 1. ročníku studia
přírodovědných předmětů na vysokých školách. Byli dotazování jak studenti, tak i
vysokoškolští pedagogové, zda jsou takovéto kurzy na vysokých školách nabízeny, zda
studenti tyto kurzy navštěvují, popř. zda by byl o takovéto průpravné kurzy zájem a jaký by
měl být jejich obsah (kritická místa kurikula středních škol). Je známo, že v ČR je
diskutována úroveň znalostí matematiky absolventů středních škol, zda mají potřebné
kompetence pro studium technických oborů, popř. fyziky na technických vysokých školách a
přírodovědeckých fakultách (aktuálně také zrušení povinné maturity z matematiky). Je
zajímavé porovnat tuto situaci s tím, zda podobné problémy řeší zahraniční vysoké školy a
popř. jaké kurzy jsou na vysokých školách nabízeny, na jaké učivo je kladen důraz. Uvedeme
příklady nabídky doplňkových kurzů na Přírodovědecké fakultě v Olomouci a příklady
z Rakouska, Itálie a Litvy.

Speaker: Holubová R. (Přírodovědecká fakulta Univerzity Palackého Olomouc)

44 STRATÉGIE ZVOLENÉ ŠTUDENTMI PRI TVORBE KOMENTÁROV K TICHÝM VIDEÁM

Konštruktivistické prístupy, ktoré sa v súčasnosti uplatňujú vo vzdelávaní v podobe
bádateľsky orientovanej výučby, zdôrazňujú okrem rozvíjania porozumenia aj rozvoj
zručností a spôsobilostí súvisiacich s činnosťami, ktoré vedú ku konštrukcii poznatkov. Počas
prípravy študentov učiteľstva fyziky sa však často stretávame so situáciou, kedy študent
uprednostňuje vyučovacie stratégie, ktorými si počas svojho vzdelávania prešiel on sám, a má
tendenciu ich napodobňovať. Preto považujeme za dôležité poskytovať študentom učiteľstva
neustálu spätnú väzbu a vzor v konštruktivistickom sprístupňovaní poznatkov. Jednou
z viacerých príležitostí, kedy môžeme takúto spätnú väzbu našim študentom poskytnúť, je aj
realizácia aktivít s tichým videom. Tiché video je typ úlohy, v ktorej študenti nahrávajú
komentár k videu trvajúcemu spravidla jednu až dve minúty, zobrazujúcemu nejaký fyzikálny
jav, pokus, experiment. Príspevok obsahuje javovú analýzu, na základe ktorej sme určili
stratégie zvolené študentmi učiteľstva fyziky pri tvorbe komentárov k trom tichým videám.

Speaker: Gorčáková S. (Katedra didaktiky matematiky, fyziky a informatiky, FMFI UK, Bratislava)

45 Využití konceptuálních úloh a grafického znázorňování v úvodním kurzu kvantové fyziky

V poslední době se i ve vysokoškolské výuce, zejména v úvodních kurzech během prvních let
studia, objevuje posun od tradičně pojaté výuky k aktivizujícím výukovým formám. Jejich
prostřednictvím se prohlubuje konceptuální pochopení základních myšlenek, které se tak
vzájemně doplňuje s řemeslným zvládnutím konkrétních technik řešení úloh typických pro
dané fyzikální téma. Výzkumy prováděné v zahraničí ukazují, že tento přístup má pozitivní
efekt jak na pochopení probírané látky, tak na schopnost řešit tyto úlohy.
Konceptuální a aktivizující přístup využíváme ve výuce úvodního kurzu kvantové fyziky pro
budoucí učitele již několik let. Velkou výzvou zůstává shánění vhodných materiálů –
konceptuálních úloh, otázek do diskuze, námětů na skupinovou práci či vhodných nástrojů
pro vizualizaci jednotlivých problémů. V našem případě je navíc velmi vhodné používat
materiály v češtině, aby si budoucí učitelé dostatečně zažili terminologii i způsoby
diskutování, protože ve své praxi se budou muset obejít bez matematického aparátu, který
tvoří přirozenou a jedinou dostatečně výstižnou „řeč“ kvantové fyziky.
V příspěvku představíme ucelenou kolekci konceptuálních úloh i vhodných nástrojů a
vizualizací vytvořených jak na základě zahraničních zdrojů, tak vyvinutých přímo ve
zmíněném kurzu. Tyto materiály jsou volně dostupné všem zájemcům a mohou tak obohatit
výuku úvodních kurzů kvantové fyziky i na dalších školách a oborech.

Speaker: Koupilová Z. (Katedra didaktiky fyziky MFF UK, Praha)

Využití konceptuálních úloh a grafického znázorňování v.pdf

Využití konceptuálních úloh a grafického znázorňování v.pptx

46 Smart biometric recording system for real-time evaluation of motility on organism with knee pathology

Lab rats and rabbits are irrepleceable models for study of the ortopedic pathologies.
Traditional analysis of these pathologies is based on postmortem histological analysis or X-
ray or invasive sampling, however modern monitoring of orthopedic pathology and
regeneration needs the smart and noninvasive methods for quantification of the motility of
the limbs and organism. Advances in imaging technologies have enhanced our posibilities to
quantify the typical movement of the organism.
Lab animals were hold in typical lab cage. We developed an autonomous optical setup which
recorded animal position and displayed the trajectory and typical characteristic of the
movement (speed, acceleration, shading of the walls of cage, rocognition of biorhytmic
period).
The system was based on the HD 10 fps camera. Export of the frames was commited to
OpenCV and mathematical conversion of motion to x-y coodinates was curbed by set of
Python utlilities.
Comparison of animals with deffects and healthy animals gives basic criterion for automatic
recognition of patholgical state and basic criterion for evaluation of regeneration process.
Upgrade of these biometric system should be used also for clinical and home rehabilitation in
the future.
Supported by the Ministry of Education, Youth and Sports project “FIT” (Pharmacology,
Immunotherapy, nanoToxicology) CZ.02.1.01/0.0/0.0/15 003/0000495

Speaker: Skopalík J. (Dept. of Biomedical Engineering, Faculty of Electrical Engineering and Communication, University of Technology, Brno)

Parallel sessions: jaderná a částicová fyzika

47 Measurements of open charm hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV by the STAR experiment

At RHIC energies, charm quarks are primarily produced in hard partonic scatterings at early
stages of ultra-relativistic heavy-ion collisions. This makes them an ideal probe of the Quark-
Gluon Plasma (QGP) produced in these collisions, since they experience the whole evolution
of the hot and dense medium. STAR is able to study the interactions of charm quarks with the
QGP through direct reconstruction of hadronic decays of D ± , D 0 , D s , and Λ c ± hadrons. This is
possible thanks to an excellent pointing resolution provided by the Heavy Flavor Tracker.
In this talk, we will present the most recent results on open charm hadron production
from the STAR experiment. In particular, we will discuss the nuclear modification factors of
D ± and D 0 mesons which give access to the charm quark energy loss in the QGP. We will also
discuss D s / D 0 and Λ c ± /D 0 yield ratios as functions of transverse momentum and collision
centrality which help us understand better the charm quark hadronization process in heavy-ion
collisions. In addition, we will present the rapidity-odd directed flow of D 0 mesons, which can
be used to probe the initial tilt of the QGP bulk and effects of early-time magnetic field.

Speaker: Vaněk J. (Nuclear Physics Institute, Czech Academy of Sciences, Rez)

CCSP2020_Vanek_final.pdf

48 RECENT RESULTS OF INCLUSIVE JET PRODUCTION IN AU+AU COLLISIONS AT √S NN = 200 GEV BY THE STAR EXPERIMENT

It has been established that the Quark-Gluon Plasma (QGP), an exotic state
of deconfined matter, is created in high-energy heavy-ion collisions. Jets are a
very important probe of this hot and dense nuclear matter, since they emerge
from the fragmentation of hard-scattered partons (quarks and gluons) that are
created during the early stages of the collisions. Therefore, measurements of
modifications to jet properties in heavy-ion collisions relative to those in proton-
proton collisions can provide insight into understanding interactions between
hard-scattered partons and the QGP.
This talk aims to present recent results of jet production in Au+Au collisions
at √s NN = 200 GeV by the STAR Collaboration at the Relativistic Heavy Ion
Collider. We will focus on the measurement of inclusive jet production as a
function of transverse momentum (p T ) of jets and collision centrality. Jets
are reconstructed using charged tracks from the Time-Projection Chamber and
neutral energy from the Barrel Electromagnetic Calorimeter towers, using the
anti-k T algorithm with jet resolution parameter R = 0.2, 0.3, and 0.4. The
large combinatorial background is suppressed by requiring a high-p T leading
hadron in accepted jet candidates. Jet yield suppression is observed for central
relative to peripheral Au+Au collisions, which is attributed to medium-induced
parton energy loss. The measured distributions are compared to theoretical
calculations incorporating jet quenching, which will improve our understanding
of medium-induced energy loss of jets at RHIC energies.

Speaker: Líčeník R. (Nuclear Physics Institute, Czech Academy of Sciences, Řež)

InclusiveJets_RL_CCSP20_final.pdf

49 Search for jet quenching effects in high-multiplicity proton-proton collisions at √s = 13 TeV

QCD jets are modified ("quenched") by their interactions with the quark-gluon plasma (QGP)
formed in high-energy nuclear collisions. The measurement of jet quenching in small collision
systems can tell us about the limits of QGP formation and the nature of equilibration in QCD,
but to date no significant jet quenching has been observed in small systems. In this talk, the
ALICE Collaboration reports results of a novel approach to jet-quenching measurements in
high-multiplicity pp collisions at √s = 13 TeV, searching for modification of di-jet azimuthal
acoplanarity measured by the semi-inclusive distribution of jets recoiling from a high-p T
hadron. Charged-jet reconstruction is carried out using the anti-k T algorithm with R = 0.4 and
a data-driven statistical method is used to correct the measured jet yield for uncorrelated
background, which includes multi-partonic interactions. High-multiplicity (HM) pp events are
selected based on charged-particle multiplicity registered in forward scintillator detectors and
their acoplanarity distributions are compared to that for Minimum Bias (MB) events.
Significant azimuthal broadening is observed in HM collisions, consistent with jet quenching.
However, qualitatively similar features are also seen in pp collisions generated by the
PYTHIA Monte Carlo event generator which does not include the simulation of jet quenching
or any other QGP effects. We will discuss the current status of this analysis and prospects to
understand the origin of this striking phenomenon.

Speaker: Křížek F. (ÚJF AV ČR, Řež)

slides_v0.pdf

50 IDENTIFYING HEAVY-FLAVOR JETS USING VECTORS OF LOCALLY AGGREGATED DESCRIPTORS

Jets of collimated particles arising from hard scattered partons have been studied extensively
in hadron collisions. Jets serve a multitude of purposes as they are utilized in fundamental
studies of the Standard Model (SM) and in searches for new particles. Recently, studies of jet
interaction with the quark-gluon plasma (QGP) created in high energy heavy ion collisions are
of growing interest, particularly towards understanding partonic energy loss in the QGP
medium and its related modifications of the jet shower and fragmentation. Since the QGP is a
colored medium, the extent of jet quenching and consequently, the transport properties of the
medium are expected to be sensitive to fundamental properties of the jets such as the flavor of
the parton that initiates the jet. Identifying the jet flavor enables an extraction of the mass
dependence in jet-QGP interactions. We present a novel approach to tagging heavy-flavor jets
at collider experiments utilizing the information contained within jet constituents via the
JetVLAD model architecture. We show the performance of this model as characterized by
common metrics and showcase its ability to extract high purity heavy-flavor jet sample at
various realistic jet momenta and production cross-sections.

Speaker: Ponimakin G. (Nuclear Physics Institute of the CAS, Rez)

ponimatkin_netvlad.pdf

51 Recent results of Upsilon production measured with the STAR experiment

Heavy-ion collisions allow to recreate conditions present in the universe shortly after the Big
Bang when the quark-gluon plasma can be formed. The properties of such plasma can be
studied using Upsilon mesons. Each of Upsilon states is expected to dissociate at a different
temperature reached in the plasma, through Debye-like screening of color charges. Thus, their
production yields are suppressed to different levels with respect to the yield in p+p collisions.
Additional cold nuclear matter effects can be studied in p+A or d+A collisions. Furthermore,
the production mechanism of these heavy mesons is not fully understood and this can be
studied in p+p collisions as well.
In this talk, we will present an overview of recent measurements on the production of Upsilon
states by the STAR experiment. These include a comprehensive study performed in Au+Au,
p+p, and p+Au collisions at p √s NN = 200 GeV as well as p+p collisions at √s = 500 GeV.

Speaker: Kosarzewski L. (Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague)

Upsilon_LK_2020_9_9_v6Kosarzewski.pdf

12:10 Lunch

Parallel sessions: didaktika fyziky

52 PROJEKT IT AKADÉMIA VO SVETLE ZMIEN VO FYZIKÁLNOM VZDELÁVANÍ

V súčasnosti častokrát skloňované problémy s prírodovedným vzdelávaním sú v centre
pozornosti národného projektu IT Akadémia, ktorého hlavným cieľom je vytvorenie modelu
vzdelávania pre aktuálne a perspektívne potreby vedomostnej spoločnosti a trhu práce so
zameraním na informatiku a digitálne technológie. V rámci príspevku predstavíme dva
kľúčové ciele projektu: inovácia vzdelávania matematiky, informatiky a prírodných vied na
základných a stredných školách a príprava učiteľov, v rámci ktorých sa sústredíme na
fyzikálne vzdelávanie. Prvý z cieľov je zameraný na aktualizáciu obsahu, metód a foriem
výučby. Rozsiahla zbierka metodických materiálov pre výučbu je vytvorená na princípoch
aktívneho žiackeho poznávania, zmysluplného využívania digitálnych technológií
a využívania stratégií formatívneho hodnotenia žiakov. Vytvorené metodické materiály sú
v širokom meradle implementované a overované vo výučbe. Spätná väzba získaná
z overovania a vzájomná spolupráca učiteľov z praxe a pracovníkov Univerzít
vychovávajúcich budúcich učiteľov má napomôcť k reálnemu uplatneniu vytvoreného modelu
vzdelávania v praxi. Nato, aby boli tieto zmeny úspešné, je však potrebné motivovať
a pripraviť predovšetkým učiteľa, ktorý vo vzdelávaní zohráva kľúčovú úlohu. Z uvedeného
dôvodu je vytvorený vzdelávací program, v rámci ktorého sa učitelia fyziky vzdelávajú
v oblasti metód bádateľsky orientovanej výučby, digitálnych technológií a hodnotenia
výsledkov vzdelávacieho procesu. V príspevku predstavíme základné myšlienky a ukážky
vytvorených metodických materiálov a koncepciu vzdelávania učiteľov fyziky.

Speaker: Ješková Z. (Prírodovedecká fakulta UPJŠ, Košice)

53 VÝSKUM ÚROVNE POZNÁVACIEHO ZÁUJMU ŽIAKOV O FYZIKU

Predkladaný príspevok je venovaný pedagogicko-psychologickej téme záujmu, ako jedného
z významných činiteľov zohrávajúcich dôležitú úlohu v procese samostatného žiackeho
bádania a učenia sa. Autori príspevku sústreďujú svoju pozornosť na záujem žiakov o
predmet školskej fyziky. Dôraz pritom kladú na poznávací záujem. Hlavným cieľom
príspevku je zistiť prítomnosť poznávacieho záujmu o fyziku na základných školách
a následne určiť aktuálny stupeň jeho rozvoja. Na základe skutočnosti, že problematika
poznávacieho záujmu v súčasnosti nie je v slovenskej literatúre metodicky dostatočne
spracovaná, opierajú sa autori vo svojom výskume o metodiku I.J. Laninovej, ktorá
vymedzuje tri základné úrovne poznávacieho záujmu. Vzhľadom na všeobecne známy fakt,
že fyzika patrí medzi menej obľúbené predmety, doplnili autori príspevku Laninovej
klasifikáciu ešte o ďalšiu, štvrtú, úroveň záujmu – tzv. nulový poznávací záujem,
odpovedajúci absolútnemu nezáujmu žiaka o tento predmet. Za účelom naplnenia vytýčeného
výskumného cieľa pripravili autori vlastný neštandardizovaný dotazník určený predovšetkým
pre žiakov siedmeho ročníka základných škôl. Analýza a vyhodnotenie výsledkov
dotazníkového šetrenia sú súčasťou tohto príspevku. Autori v ňom prezentujú svoje zistenia
týkajúce sa jednotlivých úrovní poznávacieho záujmu. Okrem toho, zaoberajú sa aj
porovnávaním a skúmaním možného vplyvu niektorých faktorov ako pohlavie či lokalita
školy na rozvoj poznávacieho záujmu.

Speaker: Kľučarová A. (Katedra fyziky, matematiky a techniky, Fakulta humanitných a prírodných vied, Prešovská univerzita v Prešove)

54 MOŽNOSTI HODNOTENIA ARGUMENTOV ŽIAKOV V RÁMCI VYUČOVANIA FYZIKY NA ZÁKLADNEJ ŠKOLE

Človek je spoločenská bytosť a integrálnou súčasťou spoločenského života je aj komunikácia.
Pri komunikácií musíme často zdôvodňovať svoje tvrdenia, presviedčať iných o ich
pravdivosti – argumentovať. Schopnosť argumentovať však nie je schopnosť, ktorá je človeku
daná pri narodení. Je však možné ju rozvíjať a zlepšovať napríklad tým, že žiaci počas hodín
vyjadrujú svoje názory pri riešení rôznych príkladov, alebo na základe niektorých faktov
predložia svoje tvrdenia. Na vyučovaní fyziky žiaci často majú uviesť svoje predpoklady,
vysloviť hypotézy, alebo vysvetliť rôzne javy a deje. Podľa cieľov predmetu fyziky v štátnom
vzdelávacom programe by mali byť spôsobilosti žiakov argumentovať rozvíjané počas
vyučovania fyziky. V príspevku sa pozrieme na to, ako vyučovanie fyziky reaguje na
požiadavku rozvíjania tejto kompetencie v našom vzdelávacom systéme na Slovensku. Na
zistenie úrovne argumentácie sme najprv stanovili kritériá, na základe ktorých možno
hodnotiť argumenty žiakov. Uvedieme ukážku konkrétnych odpovedí žiakov na fyzikálne
úlohy, v rámci ktorých žiaci potrebovali uplatniť argumentáciu, a ich hodnotenie.

Speaker: Kiss T. (Oddelenie didaktiky fyziky, Fakulta matematiky, fyziky a informatiky,Univerzita Komenského, Bratislava)

55 PROBLEMATIKA KLASIFIKÁCIE VÝKONOV ŽIAKA V NEŠTANDARDIZOVANOM DIDAKTICKOM TESTE

Hodnotenie, ako súčasť výchovno-vzdelávacieho procesu, je v poslednej dobe značne
diskutovanou témou medzi odborníkmi v didaktike, učiteľmi, žiakmi, rodičmi ale i v celej
spoločnosti. Diskutovanou témou je najmä úloha hodnotenia, jeho funkcie a postavenie vo
výchovno-vzdelávacom procese. Taktiež sa vedú úvahy, či je hodnotenie v podobe, akej sa
realizuje, objektívne a naozaj posudzuje a klasifikuje žiakov podľa vhodných kritérií tak, aby
boli rovnaké výkony žiakov hodnotené totožným klasifikačným stupňom. Proces hodnotenia
a klasifikácie žiackych výkonov považujú učitelia za jednu z najnáročnejších úloh učiteľského
povolania. Tento fakt je potvrdzovaný viacerými výskumami. Príspevok sa zameria na
problematiku náročnosti klasifikácie výkonov žiakov v neštandardizovanom didaktickom
teste. V realizovanom prieskume sme analyzovali klasifikáciu výkonov žiakov
v neštandardizovaných testových úlohách študentami učiteľstva na FMFI UK. Úlohou
prieskumu bolo porovnať jednotlivé hodnotenia navrhnutého neštandardizovaného
didaktického testu študentami učiteľstva medzi nimi navzájom a s hodnotením podľa
navrhnutej schémy hodnotenia, ktorá vychádza z revidovanej Bloomovej taxonómie. Študenti
učiteľstva hodnotili výkony žiakov v didaktickom teste bez kľúča hodnotenia a správnych
odpovedí. Do prieskumu sa zapojilo aj niekoľko učiteľov fyziky z praxe a získané dáta sme
taktiež podrobili analýze. V príspevku uvedieme priebeh prieskumu, získané výsledky
a odporúčania pre pedagogickú prax, ktoré z prieskumu vyplývajú.

Speaker: Čevajka J. (Fakulta Matematiky, Fyziky a Informatiky, Univerzita Komenského v Bratislave)

56 CO NÁM FYZIKOVÉ CHTĚJÍ ŘÍCT K FYZIKÁLNÍMU VZDĚLÁVÁNÍ NA STŘEDNÍCH A ZÁKLADNÍCH ŠKOLÁCH

Cílem výzkumu, o jehož části pojednává tento příspěvek, je zjistit představy zainteresovaných
aktérů o fyzikálním kurikulu. Mezi tyto aktéry patří mimo jiné fyzikové–vědci, další
přírodovědci, didaktikové fyziky a učitelé fyziky. Na základě sběru a analýzy jejich představ
budou formulovány podněty k proměně současného kurikula fyziky pro základní a střední
školy.
Cílem příspěvku je zprostředkovat zkušenosti se sběrem a analýzou dat od
fyziků–vědců. Podněty vzešlé od této skupiny aktérů mohou přispět k hlubší reflexi
fyzikálního vzdělávání, protože fyzikové stojí do značné míry mimo oblast vzdělávání, zato
jsou výrazně ukotveni v oboru. Výzkumný problém byl formulován následující otázkou: Co
podle českých fyziků by měla zahrnovat výuka fyziky na základních a středních školách?
Data byla získána prostřednictvím rozhovorů v rámci metodologie zakotvené teorie. Výsledky
této části výzkumu budou využity k výzkumu mezi dalšími skupinami aktérů a měly by
vyústit ve formulování doporučení k tvorbě učebnic fyziky.
Jako předběžné závěry rozhovorů, které byly provedeny s 29 z 60 oslovených fyziků,
můžeme uvést následující podněty pro výuku: výrazné propojení výuky fyziky s běžným
životem; provádění žákovských experimentů; výuka menšího počtu témat, zato v širších
souvislostech; společné vzdělávání různých skupin žáků; zajímavost pro žáky; zařazování
současné fyziky, včetně dosud nevyřešených problémů; podpora mimoškolních aktivit.

Speaker: Kolář P. (Matematicko-fyzikální fakulta, Univerzita Karlova, Praha)

Parallel sessions: fyzika pevných látek

57 SOFT MAGNETIC COMPOSITES: PREPARATION, PROPERTIES AND APPLICATIONS

Nepretržitý pokrok v oblasti magneticky mäkkých materiálov prináša nové možnosti ich
využitia v modernej elektrotechnike a elektronike. Cieľom hľadania progresívnych materiálov
je snaha o zníženie ekonomických nákladov na ich výrobu a prevádzku z nich zhotovených
výrobkov v priemyselných aplikáciách. Magneticky mäkké kompozity (MMK) vyrobené
práškovou metalurgiou otvárajú nové možnosti pri navrhovaní a výrobe dielov aj pre nové
typy elektromotorov. Vďaka vysokému elektrickému odporu majú MMK v aplikáciách s
vysokofrekvenčným premagnetovaním nižšie celkové magnetické straty v porovnaní
s klasickými materiálmi. Za magnetické vlastnosti feromagnetík je zodpovedná ich štruktúra,
fyzikálne vlastnosti, doménová štruktúra a jej reakcie na magnetické pole. Tieto vlastnosti je
možné zlepšiť alebo optimalizovať správnou voľbou a vhodným spracovaním magneticky
mäkkého materiálu. MMK sa skladajú z jednotlivo obalených feromagnetických častíc
prášku, ktoré sú pokryté elektricky izolačnou vrstvou. Súčasný výrobný postup zahŕňa
lisovanie prášku do konečného tvaru a tepelné spracovanie, ktorého cieľom je uvoľnenie
napätí indukovaných v  priebehu lisovania. Základné metodiky skúmania magnetických
vlastností sú meranie hysteréznych slučiek v širokom pásme frekvencií a použitie
impedančnej spektroskopie. Koncept MMK založený na využití izolačných vlastností
povrchovej vrstvy častíc môže priniesť výrazné výsledky v oblasti prípravy feromagnetík
rôznorodých tvarov s optimalizovanými vlastnosťami pre konkrétne aplikácie.

Speaker: Füzer J. (Ústav fyzikálnych vied, Prírodovedecká fakulta, Univerzita P. J. Šafárika, Košice)

58 NOVEL DIRECTIONS IN STUDIES OF ELECTRON-HOLE LIQUID IN SEMICONDUCTORS: WIDE GAP AND 2D MATERIALS

The low-temperature electron-hole plasma may undergo phase transition to the liquid state:
the electron-hole liquid (EHL). The transition is allowed in dense plasma below critical
temperature T C and it exists only in the thermodynamic limit, i.e. when the lifetime of the
electron-hole system is long enough to reach the thermal equilibrium. For that reason, the
macroscopic and relatively long-lived EHL is exclusively observed in the indirect
semiconductors. This liquid phase is the two component degenerate Fermi liquid. EHL has a
form of spatially separated “droplets” within a cloud of EHP or excitons. In close analogy
with conventional liquids EHL has constant density at given temperature – it is related to the
quasiparticle distance for which their energy is minimized. Decay of EHL droplets via
electron-hole recombination is faster than decay of free excitons - fortunately, this decay
includes radiative recombination processes giving rise to photoluminescence (PL) which is
the most important messenger bringing information on EHL. The investigation of the
intriguing new “matter” was conducted mostly in 1970ies in Si and Ge. EHL was later
observed also in low-dimensional semiconductor structures. Here we present recent results on
wide-gap semiconductors (especially 4H-SiC) and the graphene-like materials like MoS 2 .

Speaker: Valenta J. (katedra chemické fyziky a optiky, Matematicko-fyzikální fakulta, Univerzita Karlova, Praha)

59 NITRIDE MULTIPLE QUANTUM WELL CHALLENGE

Nitride semiconductor heterostructures are widely used for light-emitting, high-power and
high-frequency applications. But InGaN/GaN multiple quantum well (QW) structures are also
potential candidates for scintillation detectors. This application needs completely different
design of the heterostructure in comparison with LED one. It opens new problems that have
not been solved yet. Main technological challenge for scintillator structure design is the
demand for thick active regions with a higher number of QWs compared to that for LED
structures due to the high penetration depth like high energy electrons or X-ray radiation.
Another challenge is usually extremely low excitation intensity of ionizing radiation. Under
such conditions, the excitonic QW luminescence can have even lower intensity than different
kinds of defect bands originating either in GaN or in InGaN QWs. Our ability to realize
scintillators on an InGaN/GaN base will be presented and influence of number of QWs in the
structure on luminescence properties will described and discussed.

Speaker: Oswald J. (Institute of Physics CAS, v.v.i., Prague)

15:10 Coffee break

60 Zahájení vernisáže BeInspired

VERNISAZ.pdf

Poster session: opening

61 Poster session - opening

POSTEROVÁ SEKCIA.pdf

Prezentáci.pdf

Prezentáci.pptx

62 BIPARTITE ENTANGLEMENT IN THE SPIN-1/2 ISING-HEISENBERG PLANAR LATTICE CONSISTING OF INTER-CONNECTED TRIGONAL BIPYRAMIDS

The present work deals with the exactly solvable spin-1/2 Ising-Heisenberg model on an
infinite but regular two-dimensional lattice composed of identical inter-connected bipyramidal
plaquettes with the aim to clarify a bipartite entanglement between the Heisenberg spins at
zero as well as finite temperatures. The quantity called concurrence is used as an indicator for
determining a strength of this quantum-mechanical correlation.
It is demonstrated that the Heisenberg spins of each bipyramidal plaquette can be mutually
entangled at zero temperature only if the two-fold degenerate spontaneously ordered quantum
phase characterized by a symmetric quantum superposition of three possible up-up-down (or
down-down-up) states of these spins is stable. Otherwise, the bipartitite quantum
entanglement of the Heisenberg spins is totally absent. Interestingly, the entanglement
between the Heisenberg spin pairs persists also at finite temperatures, even far above the
critical temperature of the model if the exchange anisotropy between these spins is
sufficiently strong. The entangled Heisenberg spin states can also be thermally activated
above non-entangled ground state if the values of the exchange anisotropy parameter are
taken sufficiently close to the boundary with the quantum ground-state phase.

Speaker: Gálisová L.galisova.lucia@gmail.com (Institute of Manufacturing Management, Faculty of Manufacturing Technologies with the seat in Prešov, Technical University of Košice)

poster_Galisova.pdf

63 BROWNIAN MOTION IN A BATH AFFECTED BY AN EXTERNAL HARMONIC POTENTIAL

The Brownian motion of a particle in a bath of other particles is effectively described by the
generalized Langevin equation (GLE). Following Kubo, it is usually assumed that if external
forces act on the system, they do not affect the thermal force and the memory function that
enter the GLE. The action of such forces is restricted to the Brownian particle (BP), leaving
the bath particles unaffected by the external field. However, there are many physical
situations, when not only the BP but also the bath particles are subjected to the external field.
We show that for stationary systems in a harmonic potential the corresponding generalization
of the Zwanzig-Caldeira-Legget theory leads to the GLE for which Kubo’s fluctuation-
dissipation theorem remains valid but both the memory function and the thermal force depend
on the elastic constant of the confinement potential. As a result, the correlation functions
describing the random motion of the BPs change in comparison with those in the original
model as well. We discuss possibilities to calculate these functions and show several specific
solutions for them depending on the frequency distribution of the bath oscillators and the
coupling between the bath and the BP.

Speaker: Tóthová J. (Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Košice)

64 CALDEIRA-LEGGET MODEL FOR PARTICLE-BATH SYSTEMS IN THE PRESENCE OF A MAGNETIC FIELD

The Brownian motion of a particle immersed in a bath of charged particles is considered when
the system is placed in a magnetic field. The widely accepted Caldeira-Legget particle-bath
model is modified so that not only the charged Brownian particle (BP) but also the bath
particles respond to the external field. For stationary systems, two equations for the BP
motion across the field are derived. They are of the type of generalized Langevin equations
with two memory functions. The time correlation function of the thermal force is connected
with one of these functions through the fluctuation-dissipation theorem but, unlike all
previous theories, it is found to depend on the external field. In the absence of the magnetic
force, the other memory function disappears. Analytical expressions are obtained for the
velocity correlation functions and other relevant quantities such as the mean square
displacement and the diffusion coefficient of the BP for different distributions of the
eigenfrequencies of the bath oscillators. Assuming the Drude distribution of the frequencies, it
is found that at long times the motion of the particle is sub-diffusive, with the exponent 1/2.
The case of the fractional thermal noise is also analyzed.

Speaker: Lisý V. (Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Košice)

65 COMPLEX VOLUME CHANGES INDUCED BY HIGH PRESSURE AND EXTERNAL MAGNETIC FIELD IN NI 2 MNSN-BASED HEUSLER ALLOY

The Heusler Ni 2 Mn 1+x Sn 1-x alloys exhibit structural martensitic transformation from cubic
(austenite) into orthorhombic (martensite) phase in a narrow composition range, 0,4 ≤ x ≤ 0,6,
only. The transformation is accompanied by a significant changes of volume, magnetization
and by large anomalies in transport properties. We have studied forced volume magneto-
striction, Joulian magnetostriction, thermal expansion and effect of high pressure on
magnetization of the Ni 1.92 Mn 1.56 Sn 0.52 alloy in wide range of temperature, magnetic field and
pressure. The pronounced decrease of magnetization under pressure, = -11.810 -3 GPa -1 ,
points to an itinerant character of magnetism of the alloy. Using the Maxwell relation, dω/dH
= - ρdM/dP, the received value of dlnM/dP can be perfectly compare with value of forced
volume magnetostriction, dω/dH = 3.1110 -6 T -1 , received by dilatometric measurement at
field above 0.3 T. The Joulian magnetostriction at low temperature and low magnetic field
(with ΔL || < 0 and ΔL ┴ > 0) confirms a competition between strengths of magnetocrystalline
anisotropy and elastic energy in martensite of Ni 1.92 Mn 1.56 Sn 0.52 that is characterized by a zig-
zag twins structure. The relevant model proposed by O´Handley will be discussed. The
observed change of volume during martensitic transformation of the alloy was verified by X-
ray diffraction measurements.

Speaker: Kamarád J. (Institute of Physics ASCR, Prague)

KČSF20-kamarad.pdf

66 Elektronická Sbírka řešených úloh z fyziky a Sbírka fyzikálních pokusů

Sbírka řešených úloh z fyziky a Sbírka fyzikálních pokusů vznikají na Katedře didaktiky
fyziky MFF UK. Jedná se o podpůrné materiály pro studenty a učitele základních, středních
i vysokých škol.
Sbírka řešených úloh z fyziky je vyvíjena již 14 let a obsahuje přes 900 úloh v češtině. Je
primárně určena vysokoškolským studentům a žákům středních škol, lze v ní ale nalézt
i úlohy na úrovni základní školy. Sbírka slouží k prohlubování a opakování učiva či
k přípravě na zápočty a zkoušky, hojně ji využívají rovněž pedagogové. Protože jedním
z našich cílů je seznamovat uživatele s technikami řešení fyzikálních úloh, obsahuje Sbírka
nejenom jejich podrobně komentovaná řešení, ale i strukturované nápovědy, ilustrativní
obrázky či interaktivní prvky.
Od roku 2015 vzniká také Sbírka fyzikálních pokusů, jejímž cílem je poskytovat učitelům
inspiraci pro experimenty na úrovni základní a střední školy. Experimenty, kterých je
aktuálně zveřejněno 165, jsou zpracovány do jednotné struktury s důrazem na videozáznam
vzorového provedení a technické a metodické poznámky. Tam, kde je to možné, obě Sbírky
propojujeme.
Dále vzniká paralelně Sbírka řešených úloh z matematiky s úlohami na vysokoškolské úrovni
a také anglické verze vybraných částí všech uvedených Sbírek.

Speaker: Snětinová M. (Katedra didaktiky fyziky MFF UK, Praha)

KCSF_Snetinova_poster.pdf

67 MÖSSBAUER SPECTROMETRY IN THE STUDY OF METALLIC GLASSES

Metallic glasses are still attracting the interest of researchers namely for their very good soft
magnetic properties. With the aim to enhance their practical applications, new compositions
are continuously scrutinized. Here, we present Mössbauer spectrometry study of a novel
Fe 51 Co 12 Si 16 B 8 Mo 5 P 8 metallic glass prepared in a form of ribbons by conventional method of
planar flow casting. Samples in as-quenched state as well as after annealing at selected
temperatures were investigated.
Mössbauer spectrometry is one of few analytical tools that can describe disordered amorphous
systems. This can be done via hyperfine interactions between nuclei and electron shells which
sensitively probe local short-range order arrangement. Experiments performed in a broad
range of temperatures provide information on the evolution of microstructure. This is
reflected by continuous modification of the hyperfine interactions from magnetic dipole
towards electric quadrupole ones. Eventually, the Curie temperature of the investigated
metallic glass can be established.
This work was supported by the grants VEGA 1/0130/20, APVV-16-0079 and by the
European Regional Development Fund-Project "Center for Advanced Applied Sciences" No.
CZ.02.1.01/0.0/0.0/16_019/0000778.

Speaker: Miglierini M. ( Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava)

68 NEW VIEW ON THE ORIGIN OF HIGH CONDUCTIVITY OF POLYANILINE FILMS PROTONATED BY HYDROCHLORIC ACID

Polyaniline (PANI) is a material known for its high conductivity and also huge range of
obtainable conductivities. In general, three types of charge carriers are considered in PANI
salt, namely holes, polarons and protons. Many authors attribute the high conductivity of acid
doped PANI to polarons [1-3]. We show that conductivity of polarons might not be
necessarily the prevailing mechanism of charge transport. In our research in order to separate
contributions from different charge carriers PANI/Si heterojunction was studied. Impedance
spectra were measured to distinguish between polaron and hole mobilities. From V-A
characteristics on PANI/Si structure contribution of polaron and hole conductivity was
calculated. Dielectric spectra of heterojunction were measured to estimate conductivity of
ions. Both measurements resulted in values in order of magnitude ~ 10 -7 S.cm -1 . On the
contrary conductivity of several S.cm -1 on films of PANI on glass substrates were obtained
using ohmic gold electrodes. To explain discrepancy between obtained values of conductivity
a model utilising redox reaction of hydrogen and chlorine was proposed and diffusion of
hydrogen and chlorine molecules in PANI films were studied.

The work was supported by the project SVV 260 444/2018 and grant GAUK No. 190119 provided by Charles

 [1] Y. Harima, R. Patil, K. Yamashita, N. Yamamoto, S. Ito, A. Kitani, Chem. Phys. Lett.
345, 239-244 (2001).
 [2] M. Chipara, G. Aldica, D. Hui, M. Dimonie, K. T. Lau, L. Georgescu, I. Munteanu,
H.Maroscoiu, J. Optoel. Adv. Mater. 6, 297–305 (2004).
 [3] J. Kim, S. Park, and N. F. Scherer, J. Phys. Chem. B112, 15576-15587 (2008).

Speaker: Rutsch R. (Department of Macromolecular Physics, Faculty of Mathematics and Physics, Charles University, Prague)

kcsf.pdf

69 PHASE BIREFRINGENCE DISPERSION FUNCTION AS A COMPLEMENTARY TOOL FOR INVESTIGATION OF NEMATIC LIQUID CRYSTAL STRUCTURE

If we put a several tens of microns thin sample of nematic liquid crystal with planar alignment
of molecules with respect to the LC cell surface in between two crossed plane polarizers,
illuminate it by white light and rotate appropriately, then using a fiber optic spectrometer we
can observe a quasi-periodic spectral distribution of intensity of light behind the output
polarizer. The spectral distribution of intensity of light emerges due to liquid crystal
birefringence. Based on the polarizability models from which imply models describing the
extraordinary and ordinary refractive indices n e a n o , respectively, the phase birefringence
dispersion function of LC in the spectral region of wavelengths without resonant frequencies
can be expressed. Comparison of the measured spectrum with that obtained by calculation
according to the model one can find parameters characterizing mean resonance (absorption)
wavelengths as well as coefficients expressing the strength of the influence of these
absorption bands to resulting birefringence. The approach could complement absorption or
ellipsometric measurements the aim of which was to characterize optical properties of a liquid
crystal sample.

Speaker: Tarjányi N. (Department of Physics, Faculty of Electrical Engineering and Information Technology, University of Žilina)

Norbert_Tarjanyi_poster_20_KCSF.pdf

70 Role of water molecules in the phase transitions in lawsonite

Lawsonite [CaAl2Si2O7(OH)2·H2O] is an uncommon mineral found in metamorphic rocks,
occurring at subduction zones, supposedly at depths of up to 250 km. It contains 11.5 wt%
water in its crystal structure. At room temperature, it is orthorhombic, crystallizing in the
Cmcm space group. Its structure contains a silicate tetrahedra framework with four formulas
in the unit cell. Each chemical formula comprises one water molecule embedded in a
structural cavity; these cavities form channels parallel with the c axis. The protons form O-H
bonds, and they may diffuse along the channels. The static and dynamic orientations of the
water molecules plays a key role in two low-temperature phase transitions—a structural one at
270 K, and a ferroelectric one at 124 K. We studied the lattice dynamics in a single crystal of
lawsonite using infrared, Raman and THz time-domain spectroscopies. We have found a
strong soft phonon mode linked to the ferroelectric phase transition. The observed unusual
hardening of other phonons with heating is linked to anomalous temperature dependence of a
unit cell parameter. In view of a dielectric anomaly identified earlier, our results show that the
ferroelectric phase transition is of mixed displacive / order-disorder type.

Speaker: Kadlec F. (Institute of Physics, Academy of Sciences of the Czech Republic, Prague)

lawsonite-v4c.pdf

71 SOLID-STATE 1 H NMR STUDY OF CORNSTARCH PLASTICIZED WITH UREA AND GLYCEROL DURING AGEING

Thermoplastic starch, a group of starch-based materials, has often been under review because
it can be used as low-cost bioplastics. Native starch is usually processed under the action of
high temperature and shear stress with addition of plasticizers such as low molecular weight
polyols and/or amide-containing molecules to obtain a moldable thermoplastic material. Such
materials are sensitive to ageing and time dependent changes in their structure are of great
importance for the use of materials in practice. In this study, solid-state magic-angle spinning
1 H NMR was used to characterize structural changes in cornstarch plasticized with glycerol
and urea during one-year ageing. It was found that widths of the signals related to urea and
glycerol CH/CH 2 groups did not change significantly while widths of the signals coming from
water and glycerol OH groups decreased by about half after one year of storage. This could
mean that urea formed stable hydrogen bonds with starch which were not affected too much
during storage whereas hydrogen bonds between glycerol OH groups and urea were disrupted
which resulted in increased mobility of glycerol and perhaps also phase separation of glycerol
and water during ageing.

Speaker: Šmídová N. (Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Košice)

Smidova_Natalia.pdf

72 VIDEOANALÝZA V STEM VZDELÁVANÍ

STEM vzdelávanie zamerané na Science, Technology, Engineering a Mathematics zahŕňa
v sebe prípravu vysokoškolsky vzdelaného absolventa technickej univerzity, ktorý v priebehu
prípravy získal zručnosti zo všetkých spomínaných oblastí. Podľa Bloomovej taxonómie
poznávacích cieľov takéto vzdelávanie je realizované na vyšších stupňoch, ako je analýza,
aplikácia a hodnotiace posúdenie. Videoanalýza, ako jedna z metód výuky či štúdia,
umožňuje rozvíjať matematické zručnosti vo fyzikálnom vzdelávaní a následne pripraviť
študentov technického zamerania pre budúcu inžiniersku prax.
Predkladaný príspevok informuje o možnostiach využitia videoanalýzy vo výuke fyziky
v inžinierskom vzdelávaní. Zároveň poukazuje na to, že využitím tejto metódy vo výuke je
možné zlepšiť u študentov chápanie pojmu sily, aplikácie Newtonových pohybových
zákonov, čo potvrdzujú aj výsledky z FCI (Force Concept Inventory) testu.

Speaker: Hockicko P. (Katedra fyziky, Fakulta elektrotechniky a informačných technológií, Žilinská univerzita v Žiline)

poster_KCSF_2020_Hockicko.pdf

73 ÚČAST ČESKOSLOVENSKA NA ZALOŽENÍ SPOJENÉHO ÚSTAVU JADERNÝCH VÝZKUMŮ

V lednu 1956 bylo Československo přizváno k účasti na založení ústavu pro jaderný, který
měl být obdobou Laboratoře Evropské organizace pro jaderný výzkum (CERN) v Ženevě pro
země tzv. lidové demokracie. Československé stranické a vládní orgány nabídku přijaly.
Na konferenci o ústavu, která se konala ve dnech 20.–26. března 1956 v Moskvě, byla
československou vládou vyslána sedmičlenná delegace vedená tehdejším ministrem
energetiky Františkem Vlasákem. Zde byla dne 26. března 1956 podepsána Dohoda
o založení Spojeného ústavu jaderných výzkumů. Československo se stalo jednou z jedenácti
zakládajících zemí ústavu.
S využitím archivních dokumentů budou v příspěvku doloženy bližší okolnosti
československé účasti na založení Spojeného ústavu jaderných výzkumů (obsah iniciačního
dokumentu, složení a návrhy československé delegace na moskevské konferenci a volba
Václava Votruby jedním z prvých dvou náměstků ředitele ústavu).

Speaker: Těšínská E. (Ústav pro soudobé dějiny AV ČR Praha)

poster-tesinska.pdf

74 ANALÝZA TOMOGRAFICKÝCH REKONSTRUKCÍ Z DAT TOKAMAKU COMPASS

Tokamak COMPASS je vybaven dvěma sadami diagnostik, které jsou rutině využívány
k počítání tomografických inverzí. Jedná se o polovodičové diody, které slouží buď jako
bolometry (měří celkový vyzářený výkon), nebo jsou vybaveny beryliovým filtrem a měří
měkké rentgenové záření.
V důsledku omezení pozorovacích úhlů je tomografická inverze na tokamacích nedostatečně
určená, a proto se k inverzi dat často využívá algoritmus Minimalizace Fisherovy informace
využívající Tichonovovu regularizaci. Tento příspěvek se zabývá analýzou takto spočítaných
inverzí pomocí metod umožňujících zkoumat časový a prostorový vývoj emisivity plazmatu.
Princip spočívá ve sledování oblastí zájmu, které mohou mít jak obdélníkový tvar, tak tvary
odvozené od tvaru magnetických povrchů. Tyto metody lze využít ke zpracování rekonstrukcí
z více diagnostik najednou.
V příspěvku budou prezentovány analýzy rekonstrukcí vybraných výbojů tokamaku
COMPASS. Analýza rekonstrukcí měkkého rentgenového záření se zaměří na pilovou
nestabilitu a vnitřní smyčkovou nestabilitu. Analýza dat z bolometrů bude zaměřena na jev
tzv. oddělení plazmatu od divertoru a na studium okrajové nestability.

Speaker: Svoboda J. (Ústav fyziky plazmatu AV ČR, Praha)

kcsf_poster_svoboda.pdf

75 EVOLUTION OF MAGNETISM IN UCo 1-x Ir x Ge SYSTEM

The uranium based intermetallics are intensively studied because of dual character of uranium
5f electrons. Unique coexistence of ferromagnetism and superconductivity has been revealed
in URhGe and UCoGe crystalizing in the orthorhombic TiNiSi-type structure. Since UCoGe
(T C =2.5 K) is very close to magnetic instability, it is a candidate to observe vanishing of
ferromagnetic order and ferromagnetic quantum critical point. The chemical substitution was
found as an effective tool to destabilize the ferromagnetic order in UCoGe by substitution on
Co site by transition metal. UCo 1-x Ru x Ge or UCo 1-x Fe x Ge systems have showed vanishing of
ferromagnetism in quantum critical point at critical concentration 30 % of substituent
element. However, in UCo 1-x Rh x Ge or UCo 1-x Pd x Ge where both parent compounds order
magnetically, finite ordering temperature is conserved, thus quantum critical phenomena have
not been observed.
We have decided to investigate UCo 1-x Ir x Ge system. Since UCoGe is ferromagnet and UIrGe
antiferromagnet, its alloy system is promising candidate to observe interesting evolution of
magnetism. We will show that UCo 1-x Ir x Ge is the first case of disappearance ordering
temperature between two magnetic parent compounds. Therefore, two quantum critical point
of different nature of ferromagnetic and antiferromagnetic-type are expected.
In order to investigate evolution of the magnetism we have prepared polycrystalline samples
throughout whole concentration range. Subsequently, we have performed measurements of
magnetization, electrical resistivity and heat capacity.

Speaker: Hovančík D. (Faculty of Mathematics and Physics, Charles University, Prague)

76 EXOMARS 2022: PLANNED MEASUREMENTS OF ELECTROMAGNETIC RADIATION ON THE SURFACE OF MARS

Dust grains in the Martial dust storms or dust devils may be electrically charged by
triboelectric effects and laboratory experiments show that under specific conditions electric
discharges might occur in the dusty Martian atmosphere. Remote measurements from the
Earth using a 34-m Deep Space Network antenna have shown a non-thermal component of
electromagnetic radiation from Mars which has been attributed to the effects of discharges in
the dust storms but observations of the radar receiver onboard the Mars Express spacecraft
showed no credible radio signals from Martian lightning between 4 and 5.5 MHz. Direct
measurements of electromagnetic radiation on the surface of Mars are needed to solve this
puzzle.
The Exomars 2022 Surface Platform instrumentation will include the Wave analyzer module,
consisting of an assembly of magnetic and electric antennae and dedicated electronics, as a
part of the Martian ground electromagnetic tool instrument. The module will be dedicated to
the measurement of electromagnetic field fluctuations in the frequency band from 100 Hz to 8
MHz. We plan to experimentally investigate possible radio emissions of atmospheric origin
generated by electrical discharges, as well as electromagnetic waves linked to the interactions
of interplanetary plasma medium with the Martian ionosphere and magnetic anomalies.

Speaker: Santolík O. (Department of Space Physics, Institute of Atmospheric Physics of the Czech Academy of Sciences)

2020jcmf_santolik.pdf

77 IMAGING HIGH-ASPECT RATIO NANOSTRUCTURES ON SOFT AND BRITTLE MATERIALS USING ATOMIC FORCE MICROSCOPY

Atomic Force Microscopy (AFM) is a powerful imaging technique which provides very high-resolution images and topological data in scales of nanometers. The quality of the obtained data is determined by quality of used AFM tip and fine adjustment of measuring parameters and settings of the machine. The measurement becomes more challenging if the AFM probe is about to approach a soft and elastic surface such as silica gel polymers (polydimethylsiloxane) or biological membrane surfaces (insect wings) which due to their properties tend to bend and vibrate under the probe during scanning. The polymers tend to stick to the bottom of the tip and confuse the software controlling piezo motors during approach causing either false approach or putting a force on the sample, so it bends to concave meniscus or even puncture the sample surface. These malfunctions become even more problematic if a dense high-aspect ratio nanopillar network occurs on such surfaces. Yet, the ability to measure raw materials without any need of surface modification (as often needed for non-conductive materials for electron microscopy) is a decisive advantage for attempting to use AFM even on such materials. Here we present AFM topography characterization of dragonfly wings nanostructure and their polymer replicas manufactured from various soft polymers.

Speaker: Černý M. (Department of chemical physics and optics, Faculty of Mathematics and Physics, Charles University, Prague)

poster_kcsf_Matej_Cerny.pdf

78 MONTE CARLO SIMULACE PRODUKCE UPSILON MEZONU

Kvarkonia jsou dúležitou sondou k vyšetřování vlastností kvark-gluonového plasmatu.
Proton-protonové srážky jsou nezbytným prostředkem k ustanovení základních vlastností,
které slouží ke studiu kvarkonií v proton-jaderných a jádro-jaderných srážek. Tento poster
prezentuje základní charakteristiky Upsilon mezonů zjištěné pomocí Monte Carlo generátorů
v proton-protonových srážkách při √ sNN = 500 GeV. Monte Carlo generátory srážek
PYTHIA a Herwig byly využity k generování dat. Hlavním cílem těchto simulací je výzkum
závislosti normalizované produkce Upsilon mezonů na normalizované multiplicitě. Závislost
na normalizované multiplicitě je vhodným nástrojem k porozumění mechanismům produkce
částic a souhry měkých a tvrdých procesů kvantové chromodynamiky.

Speaker: Češka J. (FJFI, České Vysoké Učení Technické v Praze)

Ceska_Ups_production_poster.pdf

79 PHASE TRANSFORMATIONS IN Al-Li-BASED ALLOY STUDIED BY IN-SITU TEM.

Al-Li based alloys of AA2195 type are designed mainly for aerospace applications. They
exhibit a very high strength due to a presence of strengthening precipitates of a nanometric
size. However, materials prepared by a conventional direct-chill casting and following rolling
exhibit strong crystallographic texture and inhomogeneous mechanical properties. This
inconvenient behavior could be suppressed by a direct twin-roll casting of the material to a
final gauge and subsequent precipitation annealing. Phase transformations occurring at
selected temperatures could be characterized using in-situ transmission electron microscopy
(TEM) annealing experiments. Nevertheless, the processes could be significantly influenced
by a constrained volume of thin foils used in TEM. A formation of platelike Li and Cu-rich non-
equilibrium precipitates was studied in materials annealed conventionally in a furnace and in-
situ in TEM.

Speaker: Cieslar M. (Charles University, Faculty of Mathematics and Physics)

cieslarposter.pdf

80 PROPERTIES OF LIGHTNING-INDUCED ELECTROMAGNETIC WAVES DETECTED CLOSE TO JUPITER

The Waves instrument onboard the Juno spacecraft recorded numerous cases of dispersed
electromagnetic waves generated by Jovian lightning. These waves, also known as whistlers,
propagated through ionospheric and magnetospheric plasmas before their detection by Juno
during its close approaches to Jupiter. We present observations of nearly five thousand low-
dispersion lightning whistlers detected below radial distances of 5 Jovian radii during the first
half of the Juno mission. We have found that Jovian lightning discharges occur predominantly
at mid-latitudes. We have found an asymmetry in the whistler occurrence in both
hemispheres: the average lightning stroke rate in the northern hemisphere was approximately
twice higher than in the southern hemisphere in the first quarter of the mission, but the
mysterious asymmetry surprisingly disappeared in its second quarter. This effect might be
explained by a random distribution of thunderstorms. A lack of whistlers in the tropics might
be a consequence of their propagation in field-aligned ducts which would not allow them to
reach the altitude of Juno. Generation of lightning at Jupiter’s equatorial regions might be also
suppressed due to the solar radiation received at Jupiter’s equator, which actually inhibits the
rise of warm air from within the planet into the upper atmosphere.

Speaker: Kolmašová I. (Department of Space Physics, Institute of Atmospheric Physics of the Czech Academy of Sciences)

KCSF_2020_kolmasova.pdf

81 PROPERTIES OF YELLOW BAND IN GAN LAYERS

Nitride semiconductors became the second most important semiconductor material after
silicon in the last two decades. Many daily used devices, such as blue light emitting diodes or
high electron mobility transistors in electronic devices, are based on nitride semiconductors.
Despite the nitride devices mass production, there are many open questions and not well
understood phenomena which have to be solved.
Epitaxially grown GaN layers contain different bands in their luminescence spectra. There is
very fast excitonic band and also different kinds of defect bands, which have mostly slow
decay time. Fast decay time without any slow components is necessary for many scintillation
applications. Especially defect band with the maximum emission around 2.2 eV (called
yellow band) has very slow decay time (microsecond range) and needs to be suppressed in
fast scintillators.
In our previous work [1], we have shown that different technological parameters during Metal
Organic Vapour Phase Epitaxy (temperature, carrier gas, etc.) influence properties of yellow
band quite significantly. In this work, we continue to study properties of yellow band of GaN
layers grown with different parameters. Photoluminescence, time-resolved photoluminescence
and other measuring techniques are used for investigation of yellow band properties. Origin of
yellow band will be discussed.
[1] T. Hubáček et al., J. Cryst. Growth 531 (2020) 125383.

Speaker: Hubáček T. (Institute of Physics CAS, v.v.i., Prague)

82 SHORT-RANGE CORRELATION INVESTIGATION IN DEUTERON INDUCED REACTIONS

One of the approaches to investigate the equation-of-state of dense nuclear matter is the study
of the short-range correlations of nucleons in nuclei. Short-range correlations have densities
comparable to the density in the center of a nucleon and they can be considered as the drops
of cold dense nuclear matter. Dp elastic and dp breakup processes are investigated at Internal
Target Station of Nuclotron; dp elastic process in angular range from 60 – 135 degree in c.m.
in the energy range from 400 - 2000 MeV; dp breakup reaction in angular the range from 19 –
56 degree from 300 - 500 MeV. Results which comes from analyzing powers of dp elastic
scattering show strong sensitivity to the short range spin structure of the isoscalar nucleon-
nucleon correlations. Description based on relativistic multi-scattering model provides
reasonable agreement at small and large angles but the problem is related to angles between
them.

Speaker: Janek M. (Physics Department, University of Zilina)

janek-2020kcasf.pdf

83 STRUCTURE AND GROWTH OF OMEGA-Ti NANOPARTICLES IN BETA-Ti SINGLE CRYSTALS STUDIED BY ANOMALOUS X-RAY DIFFRACTION

Nanoparticles of hexagonal  phase in bcc-Ti(Mo) single crystals ( phase) occur due to a
diffusionless athermal  to  transformation and they grow during follow-up ageing at
elevated temperatures, while the alloying atoms (Mo in our case) are expelled from the
nanoparticle volumes. We used anomalous x-ray diffraction for the study of local chemical
composition of growing  particles and we found that a Mo-rich shell at the particle/matrix
interface is created during the particle growth. Moreover, the expelled Mo atoms create a
cloud with higher Mo density around each particle and its Mo concentration profile was
studied by anomalous x-ray diffraction and small-angle scattering.

Speaker: Holý V. (Department of Condensed Matter Physics, Charles University, Prague)

PosterHoly.pdf

84 The compound [Ni(2aepy) 2 Cl (H 2 O)] Cl×H 2 O as a candidate approaching a topological quantum critical point of a spin-1 one-dimensional antiferromagnet

The idea of controlling the magnetic ground state of a spin-1 one-dimensional
antiferromagnetic (1d AFM) quantum magnets has long been of interest to physicists. In the
study of anisotropic 1d AFM systems based on Ni 2+  compounds, a series of topologically
protected quantum phases was observed, one of these phases is the topologically protected
Haldane phase [1, 2].  The magnetic ground state of such a system is sensitive to the relative
magnitude of the single-ion anisotropy (D) and the intrachain (J) exchange interaction
parameters. The D/J ratio dictates the system’s placement in one of three competing phases: a
Haldane gapped phase, a quantum paramagnet, and an XY-ordered state, with a quantum critical
point at their junction at D/J = 1. We present the study of the crystal structure and magnetic
properties of compound [Ni(2aepy) 2 Cl (H 2 O)] ClH 2 O (2aepy = 2 – aminoethylpyridine).
Hexacoordinate Ni 2+ ions form a zig-zag chain based on hydrogen bonds and running along
crystallographic b-axis.  The analysis of the experimental susceptibility using a model of spin-1
anisotropic AFM chain yielded parameter values D/k B  = 4.05 K and J/k B  = 3.55 K. A theoretical
prediction of D/k B = 3.7 K using ab initio approach is very close to our experimental value.
[1] F.D.M. Haldane, Phys. Lett. A 93, 464 (1983).
[2] F.D.M. Haldane, Phys. Rev. Lett. 50, 1153 (1983).
[3] J.L. Manson, et al., Inorg. Chem. 51, 7520 (2012).
[4] D.M. Pajerowski, et al., arXiv:2001.08555.
This work was supported by VEGA 1/0426/19, APVV-18-0197, and APVV-18-0016 projects.

Speaker: Holub M. (Institute of Physics, Faculty of Science, P.J. Šafárik University)

HOLUB_POSTER_2020_CZECH.pdf

85 THE STUDY OF LATTICE DYNAMICS IN LOW-DIMENSIONAL QUANTUM MAGNETS WITH CHAIN-LIKE CRYSTAL STRUCTURE

Current work is focused on the lattice subsystem of Cu(en)Cl 2 , Cu(tn)Cl 2 and
Cu(en)(H 2 O) 2 SO 4 (en = C 2 H 8 N 2 , tn = C 3 H 10 N 2 ), quasi-two-dimensional quantum magnets with
one-dimensional polymeric structure. Magnetic layers were described within spin = 1/2
Heisenberg models on the rectangular and zig-zag-square lattice with nearest-neighbor
couplings J 1 > J 2 . The largest spatial anisotropy R = 1-J 2 /J 1 and the strongest effect of
interlayer coupling J’ was observed in Cu(en)Cl 2 , while somewhat lower R and much weaker
J’ in Cu(tn)Cl 2 and Cu(en)(H 2 O) 2 SO 4 .
Specific heat in zero magnetic field was measured from 2 to 300 K and Raman spectra at 300
K. In Cu(en)Cl 2 and Cu(tn)Cl 2 , specific heat anomalies observed at 138 K and 160 K,
respectively, are associated with a structural phase transition. No structural phase transition
was observed in Cu(en)(H 2 O) 2 SO 4 . The contribution of acoustic modes is described within
Debye approximation with Debye temperatures Θ D = 147 K, 109 K and 93 K for
Cu(en)(H 2 O) 2 SO 4 , Cu(en)Cl 2 and Cu(tn)Cl 2 , respectively. The larger Θ D value of Cu(en)Cl 2
and the Raman shift towards higher energies correspond well with the Cu(en)Cl 2 specific heat
values which are lower than those of Cu(tn)Cl 2 in the whole temperature region. The influence
of acoustic modes on the magnetic correlations is discussed.

Speaker: Vinnik O. (Institute of Physics, P. J. Šafárik University, Košice)

Vinnik_Olha_poster.pdf

86 CHARACTERIZATION OF THIN FREE-STANDING AL-MG FILMS

Small-scale thin films are frequently used in microelectronic devices and micro-electro-
mechanical systems where they are commonly subjected to high strains during their dynamic
motion. However, mechanical behavior of thin films significantly differs from the behavior
observed in bulk materials. To understand the size dependent properties of deformation
mechanisms, characterization of the grain properties of nano-scale materials is essential along
with mechanical tests. A promising method is in-situ transmission electron microscopy
deformation, which combines mechanical tests on a nano-scale with a direct observation of
the structure even with an atomic resolution. Thin Al-based free-standing films prepared by
DC magnetron sputtering were characterized by atomic force microscopy, conventional and
in-situ transmission electron microscopy and automatic phase and orientation mapping in
TEM.

Speaker: Bajtošová L. (Charles University, Faculty of Mathematics and Physics)

bajtosposter.pdf

87 COR SYSTEM FOR COSMIC RAYS TRAJECTORIES IN MAGNETOSPHERE SIMULATION

Cosmic rays are particles, coming from space. The system COR (Cut-off rigidity) provides
access for the wider scientific community to models of simulation of cosmic ray trajectories
in the magnetosphere via a web interface. The system offers simulations of vertical directions
or, from multiple nonvertical directions covering half sphere (2Pi solid angle) with the center
of the sphere in the point of interest. The simulation particle tracing is realized in combined
internal (IGRF) and the external geomagnetic field (Tsyganenko 96 or Tsyganenko 05)
covering the years 1968 to 2020. We call this Standard simulation module. There is also a
module for simulation in an earlier period called Historic simulation module that uses a
couple of geomagnetic field approximations for last two millennia (years from 0 to 1968).
The system also contains individual trajectory visualizations for standard modules and a
magnetosphere simulation module that allows users to evaluate the magnetic field in the
magnetosphere for selected space and time range.
Simulations based on space and time ranges are also available for Standard and Historical
cosmic ray trajectories models.

Speaker: Gecasek D.

poster_Daniel_Gecasek.pdf

88 DEDICATED RUNAWAY ELECTRONS STUDIES AT THE TOKAMAK COMPASS

Runaway electrons (RE) present one of the major concerns for future fusion devices
(tokamaks), since the uncontrolled localized RE losses can compromise the integrity
of tokamak device and its further operation. Runaway electrons can emerge within a
tokamak plasma either at low density, during the discharge start-up phase or as a result of
rapid plasma termination, associated with sudden cooling causing a significant electric field
induction. In the presence of such a strong electric field, electrons can reach several tens of
MeV (kinetic energy ~ tens of MJ). The fully effective mitigation strategy was still not
identified despite the increased effort of the fusion community. Several approaches have to be
explored.
The COMPASS tokamak is an ideal device for testing such strategies and developing new
ones due to its high flexibility, advanced RE feedback, compact size and the high
reproducibility of RE scenarios. The main studied mitigation strategies are the injection of
impurities and the application of external resonant magnetic perturbations (RMPs). The
combination of mentioned mitigation strategies with emphasis on RMPs will be
examined. Conclusions about their efficiency at COMPASS will be elaborated and
basic assumptions toward larger fusion devices will be derived.

Speaker: Macusova E.

KCSF2020_macusova.pdf

89 DESIGN OF NOVEL MATERIALS: ARPES EXPERIMENTS AND THEORY

Angle-resolved photoemission spectroscopy (ARPES) is a leading experimental probe for
studying the electronic structure and complex phenomena in quantum materials. Modern
experimental arrangements consisting of new photon sources, analyzers and detectors supply
not only spin resolution but also extremely high angle and energy resolution [1]. Furthermore,
the use of photon energies from few eV up to several keV makes this experimental technique
a rather unique tool to investigate the electronic properties of solids and surfaces [2]. On the
theoretical side, it is quite common to interpret measured ARPES data by simple comparison
with calculated band structure. However, various important effects, like matrix elements, the
photon momentum or phonon excitation, are in this way neglected. Here, we present a
generalization of the state of the art description of the photoemisison process, the so called
one-step model that describes excitation, transport to the surface and escape into the vacuum
in a coherent way [3,4]. Nowadays, the one-step model allows for photocurrent calculations
for photon energies ranging from a few eV to more than 10 keV, for finite temperatures and
for arbitrarily ordered and disordered systems, and considering in addition strong correlation
effects within the dynamical mean-field theory. Application of this formalism in order to
understand ARPES response of new materials like low-dimensional magnetic structures [6],
Rashba systems [5], topological insulator materials [1], materials relevant for photo-catalysis
[8] or ultrafast femtosecond spin dynamics [7] will be shown.
In this presentation I review some of the recent ARPES results and discuss the future
perspective in this rapidly developing field. In addition I will introduce our new spin polarised
ARPES laboratory.

Speaker: Minar J.

90 INTERDIFFUSION IN ALUMINIUM – STEEL CLAD

Bonding of aluminium and steel into one single material – an aluminium-steel clad –
represents an excellent composite material, which provides high potential for applications in
automobile industry by combination of properties of respective materials – high stiffness and
strength of steel and durability, corrosion resistance, thermal capacity and high specific
strength of aluminium. microstructure. Optimal process conditions during clad strips
production should result in the formation of a continuous diffusion layer of several Fe-Al
phases. However, such layer may reduce the bonding strength and formability of the material.
Diffusion and phase transformations in aluminium - steel clad sheet prepared by twin-
roll casting were studied by means of light optical microscopy, electron microscopy and
resistometry. Effective interdiffusion coefficient was evaluated by Boltzmann-Matano method
from measured concentration profiles through the interface. Simulated results were in a direct
contradiction with in-situ TEM/SEM observations showing surprisingly a formation of Fe-Al
phases in the steel layer. Results confirm that a simple diffusion driven model could not cover
complex processes occurring at the interface.

Speaker: Křivská B.

91 INTERDIFFUSION IN ALUMINIUM – STEEL CLAD

Bonding of aluminium and steel into one single material – an aluminium-steel clad –
represents an excellent composite material, which provides high potential for applications in
automobile industry by combination of properties of respective materials – high stiffness and
strength of steel and durability, corrosion resistance, thermal capacity and high specific
strength of aluminium. microstructure. Optimal process conditions during clad strips
production should result in the formation of a continuous diffusion layer of several Fe-Al
phases. However, such layer may reduce the bonding strength and formability of the material.
Diffusion and phase transformations in aluminium - steel clad sheet prepared by twin-
roll casting were studied by means of light optical microscopy, electron microscopy and
resistometry. Effective interdiffusion coefficient was evaluated by Boltzmann-Matano method
from measured concentration profiles through the interface. Simulated results were in a direct
contradiction with in-situ TEM/SEM observations showing surprisingly a formation of Fe-Al
phases in the steel layer. Results confirm that a simple diffusion driven model could not cover
complex processes occurring at the interface.

Speaker: Křivská B. (Charles University, Faculty of Mathematics and Physics)

krivskaposter.pdf

92 NANOFLUID BASED ON A NEW GENERATION OIL

Magnetic fluids belong to special nanomaterials with many application possibilities. One of
the fields of their use is the energy industry, where the demands on the performance of
electrical equipment are constantly rising. As a result, there is a need to use modern
insulation systems. Adding nanoparticles to conventional media could be one way to obtain
them. In this study, we focused on the complex characterization of potential magnetic
nanofluids based on isoparaffin hydrocarbons extracted from natural gas. These new
generation gas-to-liquid (GTL) derived electrical insulation fluids are cleaner, chemically
stable, and the thermal conductivity values ​​of these electrical insulating fluids are higher,
indicating improved heat transfer properties. For the preparation of magnetic nanofluids, we
used sterically stabilized nanoparticles of iron oxide with a volume fraction in samples in the
range of 0.3–3.0%. The saturation magnetization, magnetic susceptibility, density, and
viscosity were investigated showing a significant enhancement with an increase of the
volume fraction. Our experimental results show that the nanoliquid prepared on the basis of
the GTL technology has a stable colloidal character that is necessary for its application as a
potential cooling medium in electro-energetics.

Speaker: Paulovičová K.

93 RECRYSTALLIZATION OF TWIN-ROLL CAST AA8079 ALUMINUM ALLOY AFTER HOMOGENIZATION

Twin-roll casting of AA8079 aluminum sheets creates non-equilibrium structure as a result of
high solidification rates. Homogenization treatments consisting of an exposure of the as-cast
material to high temperatures close to the melting point result in a redistribution of solute
atoms and a formation of a more stable structure. Newly formed equilibrium particles have
different crystallographic structure, size and also their distribution is more homogeneous.
Their features have a significant influence on softening processes and recrystallization
occurring in sheets rolled from the homogenized material. Two different processes controlling
the kinetics of recrystallization were identified by electron microscopy, light optical
microscopy and microhardness measurements. It was shown, that a particle stimulated
nucleation dominates in materials homogenized at high temperatures while a Zener drag is a
controlling process in sheets exposed to lower homogenization temperatures.

Speaker: Králík R. (Charles University, Faculty of Mathematics and Physics)

KCSF_poster_kralik.pdf

94 SEARCH FOR PSEUDORAPIDITY FLUCTUATIONS IN HIGH ENERGY NUCLEAR COLLISIONS

Emission of relativistic particles produced in central nuclear collisions in emulsion detector
has been studied for different beam energies and primary nucleus - 16 O, 20 Ne, 28 Si, 32 S, 197 Au
and 208 Pb. A preliminary study of multiplicity and target dependence of particles fluctuations
on pseudorapidity distribution in terms of the quantity  has been made. Search for the
event-by-event fluctuations of observable  and its dependence on the mass and energies of
colliding nuclei, and the degree of centrality has been performed. The comparison of
experimental data with model predictions has been made.

Speaker: Vrláková J.

poster_Vrlakova.pdf

95 STATISTICAL ERROR OF FP EQUATION SOLUTION FOR COSMIC RAYS DISTRIBUTION IN THE HELIOSPHERE

Cosmic rays propagate the heliosphere from interstellar space till orbit of planets and Sun.
The problem of their distribution, described by Fokker-Planck equation is solved by a couple
of methods, one of the most used is the stochastic method based on Ito lemma.
Presented work is focused on the estimation of statistical error of Fokker – Planck equation
solution of the 1D forward stochastic method, for evaluation cosmic rays distribution in the
heliosphere. Error dependence on simulation statistics and energy for 1AU is presented. The
1% precision criterium is defined as a function of solar wind velocity and diffusion coefficient
value. The systematic error of the FP equation is also discussed.

Speaker: Michajlenko V.

PosterMykhailenko.pdf

96 STUDY OF RING-LIKE STRUCTURES IN PARTICLE EMISSION IN RELATIVISTIC NUCLEAR INTERACTIONS

The substuctures in the emission of relativistic particles in central 197 Au and 208 Pb interactions
with Ag, Br targets in nuclear emulsions at beam momenta 11.6 and 158 A GeV/c,
respectively, have been investigated. The nonstatistical ring-like substructures of produced
particles in azimuthal plane of a collision as result of hydrodynamic waves in nuclear matter
have been searched and their parameters have been determined. The experimental results have
been compared with the results simulated by Monte Carlo method.

Speaker: Kravcakova A.

Poster Kravcakova.pdf

97 Výzkum přechodu do režimu zlepšeného udržení plazmatu na tokamaku COMPASS

Provoz v režimu s vysokým udržením energie plazmatu (H-mód) je jedním z klíčových
předpokladů pro úspěšné dosažení hlavního cíle tokamaku ITER, jímž je desetinásobné fúzní
zesílení výkonu. Přechod do H-módu však může být významně ztížen v důsledku přítomnosti
chybových polí, které v tokamaku nevyhnutelně vznikají jako důsledek nepřesností v
umístění magnetických cívek či centrálního solenoidu. Tokamak COMPASS je vybaven
světově unikátní sadou cívek pro kontrolu chybových polí, umístěných na vnější i vnitřní
straně tokamaku, a v nedávných experimentech prokázal, že za určitých okolností vede
přítomnost těchto chybových polí během přechodu do H-módu k zamknutí rotace
magnetických ostrovů a následnému kolapsu celého plazmatu. Dále se experimentálně
podařilo prokázat vliv polohy divertorové singularity magnetického pole na dosažení H-módu
skrze ovlivnění síly toků generovaných elektrickým polem, které rozbíjí turbulentní struktury
zodpovědné za většinu energetických ztrát. V neposlední řadě se připravují unikátní
experimenty pro měření potenciální vorticity, která souvisí se samo-organizací zonálních
toků, které regulují míru turbulence a mohou způsobit přechod do H-módu.

Speaker: Peterka M.

98 A SETUP FOR MEASUREMENT OF THE TOTAL REACTION CROSS SECTION

Measurements of energy dependence of the total reaction cross section with exotic, neutron-
rich nuclei are used to study the phenomena related to the structure of weakly bound neutrons
in neutron halo and neutron skin. A spectrometer „MULTI-2“ for direct measurement of the
total reaction cross section with radioactive beams is presented, together with some results
obtained on the setup. The spectrometer consists of a multi-detector telescope for the beam
projectile identification and a 4π gamma-ray spectrometer for detection of prompt gamma-
rays and neutrons accompanying nuclear reactions. The characteristics of the gamma-ray
spectrometer important for the evaluation of the measurements – registration efficiency as a
function of energy and multiplicity of emitted gamma rays, spectrometer response and a total
energy deposition were evaluated with Monte Carlo method. Results were confirmed by
measurement with 60 Co spectroscopic source.

Speaker: Siváček I.

POSTER-20KCSF2020-SIVACEK.pdf

99 DIELECTRIC SPECTROSCOPY OF TRANSFORMER OIL-BASED FERROFLUIDS WITH MN-ZN FERRITE NANOPARTICLES

Transformers are one of the significant parts of the electrical power system. As the power
transmission system is opting for high voltage high power transmission, high performance
insulating materials are drawing attention of the electrical power industry. Nanofluids, formed
by adding nanoscale particles to insulating oil, are stable and homogeneous suspensions that
present advanced performance of electrical insulation and heat dissipation. Transformer oil-
based ferrofluids with Mn-Zn ferrite nanoparticles have been characterized at different
concentrations of particles. The dielectric-spectroscopy experiments were performed on the
LCR meter in the frequency range up to 2 MHz for different AC and BC voltage. We
demonstrate changes in the observed relaxation process by applying electric field with
different intensity. Dielectric dissipation factor of ferrofluids samples was also compared. The
low-frequency relaxation process features observed in experiments was assigned to the
electric double layer polarization. How to reduce the negative effect of nanoparticles on
dielectric loss of nanofluids, needs to be investigated further.

CANCELLED!

Speaker: Karpets M.

100 H–function Calculation for Selected Spectral Bands of Oxygen

The H–function is the most important part for determining the absorption coefficient. This
article deals with the calculation of the H–function of selected bands of molecular oxygen.
Program calculations are performed on the basis of freely available data from world databases
(NIST) and book sources (e.g. Glushko, Rosen) providing the possibility of comparison.
For the structural calculations of oxygen bands, the Orca program, created at the Max–Planck
Institute by Frank Nees, et al., was selected. The outputs of this program are used by our
program NKrov2, which provides the final mathematical and graphical outputs.

Speaker: Pokorný J.

poster_pokorny.pdf

101 PHASE DIAGRAMS OF Ce 2 Pd 2 In INTERMETALLIC COMPOUND

Thanks to the specific electronic structure the rare earth-based compounds, especially
those containing Yb, Ce or Eu, often exhibit exceptional magnetic properties. In our study we
have focused on cerium-based compound Ce 2 Pd 2 In belonging to the family of R 2 T 2 X
compounds crystallizing in tetragonal Mo 2 FeB 2 -type structure. Previous studies revealed
presence of two magnetic phase transitions (�� C  ≈ 4.1 K and �� N ≈ 4.5 K) and strong dependence
of magnetic ground state on the changes of chemical composition [Giovannini,
PhysRevB2000].
We present the pressure-temperature phase diagrams both for hydrostatic and uniaxial
pressure. Hydrostatic pressure acts in the same way on the whole lattice, while the uniaxial
one allows to act solely in the chosen direction. The results are put into context with
temperature evolution of crystal lattice investigated by low temperature X-ray diffraction.
Based on these results, hydrostatic pressure is supposed to act more on the a-parameter, which
leads to approaching of atoms in the basal plane, affecting the exchange interactions in the
system and preference antiferromagnetic phase over the ferromagnetic one. On the other
hand, the uniaxial pressure acts on the parameter c showing no significant effect on the
temperatures of phase transition.

Speaker: Král P.

KCSF_poster_PetrKral.pdf

102 Pressure induced superconductivity in a CeRhSi 3 single crystal – high pressure study

Pressure-induced superconductivity in CeRhSi 3 and CeIrSi 3 has attracted a significant
attention for unconventional nature of the superconductivity in a non-centrosymmetric lattice.
All previous results, however, were limited to maximum 3 GPa of applied pressure. We focus
on a high-pressure-region behavior of the pressure-induced superconductivity in CeRhSi 3 . Our
study was performed employing the good-quality Sn-flux-grown single-crystal (electrical
current along [110]) and Bridgman anvil cell allowing to apply pressures up to 6 GPa. The
initial shift of antiferromagnetic transition to higher temperatures with applied pressure, up to
1.1 GPa; emergence of superconductivity at this pressure; subsequent decrease of Néel
temperature and increase of SC temperature with further pressure application were followed.
The critical SC temperature reaches a maximum at 2.9 GPa. No signs of magnetic transition
are observed. Further application of pressure shifts SC to lower temperatures, forming a
typical SC dome. The superconductivity is expected to be completely suppressed between 5
and 6 GPa. Measurements in magnetic fields revealed a considerable decrease of critical field
above 3 GPa, which exceeds the value of 19 T at the top of SC dome. Presented results are
summarized in the completed T-p and H-T phase diagrams, complementing previous results.

Speaker: Staško D.

Stasko_poster_CeRhSi3_KCSF2020.pdf

103 STUDY OF P3HT THIN FILM PHOTOLUMINESCENCE SPECTRA USING H-J AGGREGATE THEORY

The usual interband transitions S0–S0, S0–S1, S0–S2 can be clearly identified in the recently published photoluminescence measurements on P3HT layers. However, in many cases the spectra are characterized by weaker ripples besides these main features. We point out their possible interpretation by means of the H and J aggregates theory proposed by Spano (F. C. Spano, J. Chem. Phys. 122, 234701-234715, 2005). Such an explanation correlates with the fact that the P3HT material in a spin-coated layer consists of the amorphous phase and one or two crystalline phases depending on the substrate surface properties.

Speaker: Dr S. Kotorová (Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovičova 3, Bratislava, Slovakia)

KCSF_poster_Kotorova.pdf

104 Super-Klein tunneling of Dirac fermions through electrostatic gratings in graphene

We use the Wick-rotated time-dependent supersymmetry to construct models of two-
dimensional Dirac fermions in presence of an electrostatic grating. We show that there
appears omnidirectional perfect transmission through the grating at specific energy.
Additionally to being transparent for incoming fermions, the grating hosts strongly localized
states.

Speaker: Jakubský V.

CSF.pdf

105 Conference dinner: 19:00 - 19:30 arrival | 19:30 first toast | 21:30 end of catering | 22:00 restaurant closed

KONFERENČNÁ VEČERA.pdf

Thursday 10 September

Parallel sessions: fyzika pevných látek

106 ENHANCING GOLD BY GOLD: PLASMON ENHANCED LUMINESCENCE OF GOLD NANOCLUSTERS ON GOLD NANORODS

One of the fundamental features of nanotechnology is that properties of a certain material can
be changed just by varying its shape and size. This exactly is the case for the two types of
gold nanostructures in our study, where luminescent gold nanoclusters (AuNCs) benefit from
the presence of plasmonic gold nanorods (AuNRs). Despite the limited number of atoms,
AuNRs with characteristic dimensions ranging from ~10 to 100 nm still retain their metallic
properties. Consequently, collective oscillations of the nearly free conductive electrons (so
called localized surface plasmon resonance; LSPR) can be excited in AuNRs upon interaction
with an incoming electromagnetic radiation. In recent years, LSPR has been widely used to
enhance the optical performance of other nearby objects (e.g. surface-enhanced Raman
scattering or luminescence).
The electronic structure of AuNCs with diameter of ~1 nm is, on the other hand, rather
molecular-like, which can result in near-infrared photoluminescence from the nanoclusters.
In the present study, we attempt to increase the radiative rate in AuNCs by coupling their
emission to plasmons of AuNRs in a core@shell AuNRs@AuNCs structure. By measuring
the changes in luminescence of AuNCs upon attachment to AuNRs we demonstrate that it is
indeed possible to enhance gold by gold.

Speaker: Pavelka O. (Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague)

107 DIELEKTRICKÁ SPEKTROSKOPIA FUNKCIONALIZOVANÝCH KARBÓNOVÝCH NANORÚROK

Štúdium dielektrických parametrov vedie k lepšiemu porozumeniu polarizačných
a relaxačných javov v nových materiáloch. Táto štúdia je zameraná na mnohostenné
karbónové nanorúrky funkcionalizované magnetickými nanočasticami. Pomocou dielektrickej
spektroskopie sa študoval vplyv elektrického poľa na zmeny dielektrických parametrov
i štruktúrneho usporiadania MWCNT/Fe 3 O 4 . Frekvenčná závislosť disipačného faktora sa
merala v rámci frekvenčného rozsahu od 10 mHz do 2 MHz v rozmedzí teplôt od 15 °C do
65 ° C pomocou kapacitnej metódy. Analýza nameraných údajov sa uskutočnila pomocou
relaxačného Cole-Cole modelu. Pozorované nízkofrekvenčné relaxačné maximum
disipačného faktora je vysvetlené Schwarzovou teóriou polarizácie elektrickej dvojvrstvy
pričom s teplotou sa posúvalo do oblasti vyšších frekvencií. Elektrické pole vplýva na zmenu
elektrického dipólového momentu nanorúrok, nanočastíc a orientáciu v smere elektrického
poľa spojenú aj s tvorbou reťazcov.

Speaker: Kúdelčík J. (Katedra fyziky, Fakulta elektrotechniky a informačných technológií, Žilinská univerzita V Žiline)

108 QUANTUM DOTS GROWN BY METALORGANIC VAPOR PHASE EPITAXY

This paper focuses on quantum dots (QDs) embedded inside semiconductor heterostructures
prepared by Metalorganic Vapor Phase Epitaxy (MOVPE) technology and is based on our
contribution in [1].
Light emission from atoms/molecules in a glass matrix or in gas is strongly monochromatic.
Semiconductor direct-bandgap materials have much higher energy conversion efficiency than
the other light sources, but they have a broad band or multimode light emission spectra. QDs
inside semiconductor heterostructures can fundamentally improve the quality of spectrum,
temperature dependencies and also light efficiency emission.
The main technological procedure used for MOVPE preparation of QDs embedded inside the
heterostructure is self-assembled Stranski–Krastanov growth mode. Growth procedures and
parameters will be briefly described.
Mostly used material combination for embedded QDs is InAs QDs in a GaAs matrix.
Embedded MOVPE-prepared QDs are currently used for semiconductor lasers, optical
amplifiers, LEDs and photodetectors. High extinction coefficient of QDs is promising for
possible optical applications. QDs can operate like a single-electron transistor and show the
Coulomb blockade effect. QDs have also been suggested for quantum information processing .
QD technology is relevant to solid-state quantum computation .
[1] Metalorganic Vapor Phase Epitaxy (MOVPE): Growth, Materials Properties and Applications”,
edited by S.J.C. Irvine and P. Capper, published by Wiley (John Wiley & Sons) 2019, autumn.

Speaker: Hulicius E. (Institute of Physics, Czech Academy of Sciences, Prague)

109 Determining the alignment of thin MoS 2 layers from Raman and GIWAXS measurements

Thin MoS 2 layers grown by sulfurisation of Mo films can be aligned horizontally or vertically
depending on the initial Mo thickness. So far, the vertical alignment of MoS 2 layers has been
detected by TEM measurements. However, TEM provides information only from a very
limited area of the sample and requires time consuming and laborious sample preparation.
Alternatively, grazing incidence wide-angle X-ray scattering (GIWAXS) can be used for
detecting the layer alignment in MoS 2 thin films. Still, this technique is not widely used. We
present here that Raman spectroscopy (in combination with GIWAXS measurements) can
provide information equivalent to that from GIWAXS or TEM on the layer alignment. Raman
spectroscopy is a fast method, easy to use and needs no special sample preparation. We
present measurements of the intensity of A 1g and E 2g lines as a function of the angle between
the polarisation of the incident and scattered light in backscattering geometry. From the
measurements, a depolarisation ratio for both Raman modes was obtained, showing its
distinctive values for the two layer alignments indeed. We demonstrate the method by
specifying the alignment of MoS 2 grown on a sapphire substrate partially coated by reduced
graphene oxide flakes.

Speaker: Hulman M. ( Institute of Electrical Engineering, SAS, Bratislava)

110 WHAT CAN WE LEARN FROM COMPARATIVE CHARACTERIZATION OF MATERIALS ON THE MACRO- AND NANO-SCALE

The physical and chemical properties of materials tested on the macro- or nano-scale may
differ dramatically. For example, when measuring the Young's modulus of elasticity, we
assume an “infinite” depth of material, which is not fulfilled especially when the Young’s
modulus is measured at the nano-scale. Another example, the interaction of nanomaterials
with biological environment and their toxicity is dependent on properties of individual
nanoparticles, such as shape, surface passivation, zeta-potential (surface charge in colloidal
state), chemical reactivity etc. and conflicting results about the same nanomaterial toxicity are
published quite often. We decided to study those materials with our home-designed micro-
spectroscopy setup combined with atomic force microscopy device equipped with several
additional modules. In this contribution we would like to present our knowledge about
studying various systems at nanoscale and their comparison to bulk measurements. The new
field of nano-reconnaissance can help us to understand for example the chemical reactivity of
nanoparticles or reasons of secondary inflammatory reactions caused by deformation of
proteins in the protein corona formed on the nanoparticle in a living organism.

Speaker: Fučíková A. (Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague)

Parallel sessions: lasery, fyzikální plazma, turbulence

111 LASER – PRACOVNÍ NÁSTROJ 21.STOLETÍ

Laserové systémy prošly od svého objevení v roce 1960 dlouhou cestu a v posledních letech
se stávají stále častěji běžně využívaným pracovním nástrojem. Centrum HiLASE
Fyzikálního ústavu se od svého vzniku zaměřuje na vývoj špičkových, zejmna pulsních,
diodově buzených pevnolátkových laserů pro moderní průmyslové aplikace. Takové lasery
s vysokou účinností, středním výkonem až 1 kW a dobou trvání pulsu v řádu nanosekund až
femtosekund jsou schopny zajistit v průmyslových podmínkách výrobu rychlých
polovodičových čipů, zvýšit životnost a spolehlivost leteckých součástek, vrtat vysoce přesné
otvory pro moderní motory, vytvořit funkční a antibakteriální povrchy na řadě materiálů
a mnoho dalších.
Centrum Hilase v současné době disponuje laserovou technologií na bázi tzv. tenkých disků,
kdy laser využívá výhody účinného chlazení velkoplošných krystalů s tloušťkou pouze stovek
mikrometrů, popř. technologií kryogenně chlazených keramických desek pro pulsy s vyšší
energií. Základní emisní oblast v okolí 1030 nm může být technikami nelineární optiky
rozšířena do viditelné i střední infračervené oblasti. Přednáška shrne stav vývoje v laserovém
centru HiLASE.

Speaker: Smrž M. (Institute of Physics, Czech Academy of Sciences, Prague,)

112 VÝZKUM FÚZNÍHO PLAZMATU VE VÝBOJÍCH PLAZMOVÉHO FOKUSU

V plazmovém fokusu je husté a horké plazma vytvářeno kompresí proudu procházejícího plazmatem
vlastním magnetickým polem. Prezentované výsledky vedoucí v deuteriové náplni k fúzní DD reakci
byly prováděny v IPPLM ve Varšavě na aparatuře PF-1000, která dosahuje°neutronový zisk 10 11 A při
proudu 1 – 2 MA. Na aparatuře je využívána komlexní rentgenová, laserová, částicová a neutronová
diagnostika. Interpretace publikovaných výsledků prokázala existenci organizovaných toroidálních a
sférických struktur v komprimovaném sloupci a jejich vývoj. K produkci fúzních neutronů dochází při
vzniku a zániku těchto strurtur o hustotě 10 24 - 10 25 v m -3 a teplotách 50 -200 eV. Tyto struktury a
jejich vývoj jsou vysvětleny pomocí uzavřených proudů s poloidní a toroidální komponentou a jejich
vzájemnou přeměnou. Magnetická pole jsou generována principem magnetického dynama, podobně
jako v planetách nebo ve hvězdách. Fúzní neutrony vznikají srážkami rychlých deuteronů o energiích
stovek keV s klidovými deuterony. Mechanismus urychlení těchto částic je netepelný a v prezentaci je
vysvětlen na principu rekonekce magnetických silokřivek filamentárních proudů. Prezentované
výsledky jsou porovnávány s pozorováním energetických částic v tokamakovém, laserovém a
astrofyzikálním plazmatu.

This work was supported in part by the Research Program under Grants MSMT No. LLT17015, 8JPL19014,
CZ.02.1.01/0.0/0.0/16019/0000778 and LTAUSA17084, GACR 19-02545S, IAEA CRP RC-19253 and SGS
16/223/OHK3/3T/13.

Speaker: Kubeš P.

113 PLASMALAB@CTU - NEW FACILITIES IN SUPPORT OF FUSION EDUCATION

The contribution focuses on a new plasma laboratory, currently in commissioning phase. Its
aim is to provide doctoral and undergraduate students as well as non-fusion experts with
hands-on experience and support for their experimental research relevant to modern fusion
technology. The laboratory consists of four main sections: Electric and magnetic fields,
Plasma, Optics, and the GOLEM tokamak [1]. All the experiments support remote control
operation as much as feasible. The contribution will present the technical solutions of the
particular experiments and first measurements.

Speaker: Brotánková J. (FJFI ČVUT v Praze)

114 ANALYZING MYSTERIOUS TURBULENCE

Turbulence is one of the most fascinating phenomena in nature existing from Ångström
length-scales (quantized vortices in superfluid helium [La Mantia et al. 2016]) up to galactic
scales [Vatistas 2010]. One of the main features of turbulence is the presence of interacting
vortices of various strengths sizes and orientations. But the present description of turbulence
is based on statistical analysis of velocities or pressures. The vortex filament method is used in
numerical simulations of superfluid [Varga et al. 2017] or classical viscosity-damped
[Marchevsky 2020] turbulent flows. We introduce the approach of individual vortices into
experiments. We use the spatially resolved 2D velocity data obtained by using the
experimental method Particle Image Velocimetry (PIV) to find the individual vortices in the
turbulent field and then we analyze their properties statistically.

Speaker: Duda D. (Faculty of Mechanical Engineering, University of West Bohemia in Pilsen)

10:10 Coffee break

Parallel sessions: fyzika

115 Advanced scanning probe microscopy of low-dimensional molecular systems revealing exotic quantum states

Low dimensional materials offer very interesting material and physical properties due to
reduced dimensionality. At present, 2D materials are the focus of attention. However, 1D
systems often show far more exotic features, such as Tomanaga-Luttinger liquid, Peierls
distortion, etc.. In this talk, we will present -conjugated molecular chains of distinct
topological classes formed on metallic surfaces by on-surface synthesis, which physical
properties were investigated by low temperature UHV scanning probe microscopy supported
by theoretical analysis. We will reveal fundamental connection between topological phase
transition and the level crossing driving a variation of the -conjugation of polymers [1]. The
proximity of the quantum phase transition, in principle, allows us to design intrinsically
conductive polymers despite of the Peierls distortion.
[1] B. Cierra et al. Nature Nanotechnology. (2020). DOI: 10.1038/s41565-020-0668-7

Speaker: Jelínek P. (Institute of Physics of Czech Academy of Sciences, Prague)

116 Unusual properties of piezo-resonators at millikelvin temperature range and high magnetic fields

We present unusual properties of the commercial quartz tuning forks (QTFs) operating at
resonance frequencies of 32 kHz, 77 kHz and 100 kHz at temperature range below 1K and in
high magnetic fields up to 7.5 T. We show that in millikelvin temperature range, the quartz
tuning forks exhibit the property of the coherent oscillations. These are manifested as a
temperature-dependent, extremely accurate tune-up of QFTs resonance frequencies in 9th
order with very high frequency stability characterized by the low values of the Allan
deviations comparable with those in lasers. Even more, we demonstrate that a normalized
resonance frequency of the tuning forks manifests a universal temperature dependence, which
is independent on the magnetic field strength. This feature make the QTFs a very promising
low temperature thermometer in high magnetic fields in temperature range below 1 K while
having the B/T ratio up to 1000. We also discuss the physical origin of the observed
dependencies.

Speaker: Človečko M. (Centre of low temperature physics, Institute of Experimental Physics SAS, Košice)

117 THE MOMENTUM SPECTRUM VERSUS THE PROBABILITY FLUX DIRECTION IN QUANTUM MECHANICS

Simple examples that the direction of the momentum, defined by its spectral support in a
given state, and the direction of the probability flux may be locally uncorrelated in 1+1
dimensional space-time are given for the Schrödinger and the Dirac particle with non-zero
mass. For the zero-mass Dirac particle, they are always correlated.

---

Jednoduché příklady ukazují, že směr hybnosti, definovaný jejím spektrálním nosičem
v daném stavu, a směr toku pravděpodobnosti nemusí být lokálně korelovány pro
Schrödingerovy a Diracovy částice s nenulovou hmotností v 1+1 rozměrném prostoročase.
Pro Diracovy částice s nulovou hmotností jsou vždy korelovány.

Speaker: Dittrich J. (Nuclear Physics Institute CAS, Řež,)

Dittrich.pdf

118 PHYSICS AT FUTURE EIC EXPERIMENT

The future experimental facility EIC (Electron-Ion Collider) that will be built in Brookhaven
National Laboratory in the USA introduces new opportunities for precise study in high energy
nuclear physics. This contribution is an overview of the author’s research related to this topic.
Particularly, in this contribution, we focus on topics as nuclear shadowing, quarkonia wave
function study, or exclusive and diffractive processes.
The goal is to study various nuclear effects, such as nuclear shadowing. Nuclear shadowing is
a phenomenon of depletion of the cross section in comparison with a cross section on the
proton target. The situation is more complicated since the interaction is not completely
coherent at EIC kinematics, leading to more advanced formalism based on Green functions.
The studied nuclear shadowing is universal and will be applied in fact to most of the
processes on nuclear targets such as vector meson (VM) diffractive and, particularly,
exclusive production. The goal in such measurement is to study gluon distribution or,
generally, the universal gluon Wigner distribution. However, for that, we need to minimize
the uncertainty from VM wave functions by its and its effects detailed study such as quark-
antiquark potentials, Melosh spin rotation, or the structure of the VM vertex and the role of
the D-wave component.

Speaker: Křelina M. (FNSPE, Czech Technical University in Prague)

KCSF-Krelina-v1.pdf

Parallel sessions: fyzika pevných látek

119 VZŤAHY MEDZI ELEKTRÓNOVOU ŠTRUKTÚROU A MIKROŠTRUKTÚROU TENKÝCH VRSTIEV POLYFLUORÉNU A KOPOLYMÉRU ZALOŽENÉHO NA FLUORÉNE

V posledných rokoch vzrástol význam syntézy konjugovaných kopolymérov spájajúcich v
jednej molekule rôzne monoméry. Takéto materiály nachádzajú široké uplatnenie v
mikroelektronike aj vo fotovoltike, keďže ich cielaná syntéza umožňuje nielen vhodné
nastavenie šírky zakázaného pásu, ale aj zvýšenie účinnosti konverzie slnečného žiarenia na
elektrickú energiu spojením monomérov s dierovou a elektrónovou vodivosťou do jednej
molekuly. Aj keď v organických polovodičoch dominujú molekulové vlastnosti nad
štruktúrnymi, vzťahy medzi mikroštruktúrou tenkých vrstiev kopolymérov a ich elektrickými
vlastnosťami sú silné a stále nie plne pochopené. V tomto príspevku porovnáme elektrónovú
štruktúru a mikroštruktúru tenkých vrstiev modelového homopolyméru a kopolyméru
syntetizovaného na jeho základe. Metódami ER-EIS a GIWAXS budeme analyzovať vplyv
žíhania na vlastnosti vrstiev, menovite na ich elektrónovú štruktúru a kryštalinitu.

Speaker: Gmucová K. (Fyzikálny ústav SAV, Bratislava)

120 MAGNETIC, MAGNETOCALORIC, THERMAL AND TRANSPORT PROPERTIES OF Gd 3 Ni 2 In 4

The new polycrystalline intermetallic compound Gd 3 Ni 2 In 4 has been prepared. We have
investigated the structural, magnetic, magnetocaloric, thermodynamic and transport
properties. X-ray powder diffraction pattern displays that Gd 3 Ni 2 In 4 crystallizes in hexagonal
Lu 3 Co 2 In 4 – type of crystal structure. The presence of two magnetic transitions,
antiferromagnetic T N = 21 K and ferromagnetic T C at 55.5 K was observed in magnetization
studies. The maximal value of magnetic entropy change, -ΔS M , determined from isothermal
magnetization data in a magnetic field of 9 T is 4.57 J/kg K, which is spread over a wide
temperature range (ΔT = 61.5 K) and hence it yields to a relative cooling power (RCP) of 281
J/kg. In addition, the compound shows a significant positive magnetoresistance, MR (T = 2
K) = 44 % in magnetic field B = 9 T. Taking into account these results one could conclude
that Gd 3 Ni 2 In 4 compound is exhibiting successive reversible magnetic transitions. Thus, it may
comprise a distinct class of magnetocaloric materials as they work in a wider temperature
range than conventional refrigerant materials.

Speaker: Reiffers M. (Faculty of Humanities and Natural Sciences, Prešov University, Prešov,)

121 MICROSCOPIC ORIGIN OF LINEAR MAGNETO-OPTICAL EFFECT IN BCC FE

We present analysis of microscopic origin of magneto-optical spectra from the electronic
structure of bcc Fe. The magneto-optical (MO) permittivity spectra are obtained by the
WIEN2k code and compared to the corresponding experimental MO Kerr effect spectra. The
ab-initio spectra are given by the Kubo formula, i.e., as a result of summation over all pairs of
electronic bands and integration over the Brillouin zone that all sum up to the single MO
spectrum. We investigate what features of electronic structure contribute to the outgoing total
MO spectrum. We have also developed several novel ways of visualizing MO-related
phenomena in the Brillouin zone.
It turns out that strong MO signal comes from several isolated k-points in the Brillouin zone,
where the band degeneracy is avoided by the spin-orbit interaction. There are two major types
of MO contributions determined by the nature of the avoided degeneracy (given by topology
of the approaching bands), that contribute differently to the total MO spectrum. Both types are
visualized and their contributions to the total spectrum are demonstrated in the form of local
MO spectra.

Speaker: Stejskal O. (Faculty of Mathematics and Physics, Charles University, Prague)

122 ELECTRICAL TRANSPORT PROPERTIES OF NI 1.92 MN 1.56 SN 0.52 MAGNETIC SHAPE MEMORY MATERIAL

The Ni 1.92 Mn 1.56 Sn 0.52 belongs to a family of Heusler alloys with peculiar magnetic, structural
and transport properties that can be potentially useful for applications. They show structural
transition from high temperature cubic austenite (A) to low temperature orthorhombic
martensite (M) with significant changes of volume, magnetization, resistivity and Hall effect.
We have performed study of temperature dependence of electrical resistivity, Hall coefficient
and heat conductivity of Ni 1.92 Mn 1.56 Sn 0.52 in temperature region between 4 K and 400 K. The
ferromagnetic ordering accompanied by sharp change of resistivity T-derivative was
established below T C = 320 K. Structural A-M transition at cooling, T A-M = 282 K, induces a
large increase of resistivity and vice versa, M-A transition at heating, T M-A = 294 K, induces a
decrease of resistivity. It is worth to note that A-M transition is associated with transition
from ferromagnetic austenite to martensite with almost zero magnetization. The re-entrance of
magnetization at T c = 235 K is accompanied with any resistivity anomaly. The maximum of
resistivity around 150 K is followed by a shallow T 2 resistivity dependence. An unusual
character of temperature dependence of the Hall effect points to dramatic changes in
electronic structure during the structural transition.

Speaker: Kaštil J. ( Institute of Physics ASCR, Prague)

123 WIDE TEMPERATURE RANGE MAGNETOCALORIC EFFECT IN DY 6.5 CO 2 SI 2

We report that this alloy has been formed in three phases Dy 5 Si 3 , Dy 3 Co 2.2 Si 1.8 , and Dy 3 Co with
four successive magnetic transitions. The important role in the magnetic behavior plays
competing ferromagnetic and antiferromagnetic interactions in the alloy. The number of
successive magnetic transitions together with competing magnetic interactions exhibit
broadened magnetocaloric effect (MCE) peak with temperature width of ΔT = 83.8 and
93.2 K and consequently a large RC value of 474 and 739 J/kg, for a magnetic field change of
0–5 and 0–7 T, respectively.

Speaker: Iľkovič S. (Faculty of Humanities and Natural Sciences, Prešov)

12:10 Lunch

Parallel sessions: fyzika pevných látek

124 NIHILNOVI – A NOT SO NEW APPROACH TO DATA VISUALISATION PROMOTING PORTABLE AND SIMPLE TEXT FORMATS

With an aim of promoting open-source software and text files for data storage and processing,
the author presents a program [1] that attempts to resolve the less-than ideal situation in this
field.
The usual approach is to either load the data into a point-and-click application for scientific
plotting, or learn basics of programming and type the commands in a scientific math package.
However, manually handling larger or repeated datasets is inefficient. Programming
languages are inappropriate for trivial or interactive tasks. Less advanced programs re-
implement only a fairly limited subset of mathematical or graphical functions used in science
today. More advanced ones often bind the researcher to one particular proprietary software
and data formats.
The major novelty of the program is paradoxically in that it does almost nothing new: It does
not implement a new plotting library, nor does it promote its custom scripting language –
Python/Matplotlib/Numpy is already a popular environment for data processing.
The talk will be practically focused, with several use cases where the concept of doing
(almost) nothing new to achieve great results will be illustrated.
[1] F. Dominec: Nihilnovi source code repository (2020, 11th May), retrieved from
https://github.com/FilipDominec/nihilnovi

Speaker: Dominec F. (Institute of Physics CAS, Prague)

125 APPLICATION OF MACHINE LEARNING IN SINGLE CRYSTAL GROWTH

Development of a new material with required properties is a very complex task. Theoretical
models for growth procedure are usually not available, at least at the beginning. Therefore,
many attempts are made to achieve required properties of the material and many
characterization datasets are obtained. However, the way how the physical properties of the
material are affected by the growth conditions does not have to be straightforwardly evident.
For such a case, machine learning can be very helpful. In this contribution, applications of
several simple machine learning approaches are applied to the development process of the
InGaN/GaN scintillator structure. A properly trained neural network is capable to predict
luminescence properties from the growth parameters of the structure. This enables
optimization of the growth parameters from empirical data only. On the other hand,
understanding of underlying physics is not guaranteed but the predictions of the model can
give a clue.

Speaker: Hájek F. (Institute of Physics CAS, v.v.i., Prague)

126 IMPACT OF MACROSCOPIC PARTICLE COMPOSITION ON GAN EPITAXIAL GROWTH MORPHOLOGY AND LUMINESCENCE

We describe macroscopic defects on InGaN/GaN multiple quantum well structures caused by
accidental contamination with dust particles during the metalorganic vapour phase epitaxy.
Gallium nitride and InGaN/GaN heterostructures are promising materials for many
optoelectronic devices, such as light emitters, high-power and high-frequency electronics,
detectors of ionizing radiation, scintillators. During the preparation of these structures, great
attention is paid to optimization of the growth parameters and to reduce the density of
dislocations and point defects in this material. However, only a small number of studies were
performed on macroscopic defects due to particles fallen from the reactor chamber or
scratches from substrate polishing. Understanding the impact of each of the contaminating
elements is not only important for sample diagnostics, but it also provides insight into the
complex physical and chemical processes during epitaxy.We focus on the influence of
macroscopic defects on photoluminescence of GaN/InGaN multiple quantum well structures
and present a Raman spectroscopy study of macroscopic defect containing regions of the
samples.

Speaker: Kuldová K. (Institute of Physics CAS, Prague)

127 MULTIPLE QUANTUM CRITICAL POINTS IN CE 3 PTIN 11

The properties of the heavy fermion compound Ce 3 PtIn 11 are rather enigmatic. Not only the
compound possesses two inequivalent Ce-sites but at ambient pressure it exhibits two
successive antiferromagnetic (AFM) transitions at T 1 = 2.2K and T N = 2K, respectively [1].
Upon further cooling superconductivity is found with T c = 0.32K. Entropy analysis
conjectured the idea that the Ce2-ions are responsible for the magnetic ordering whereas the
second Ce1-ions evokes superconductivity. Here we present our recent 115 In NMR/NQR and
specific heat results. From these we infer that Ce 3 PtIn 11 possibly harbors two quantum critical
points (QCP) i.e., zero temperature phase transtitions – one close to/or at ambient pressure [2]
and one to be reached by an applied hydrostatic pressure of p c = 1.5GPa [1]. Each QCP can be
associated with a particular Ce-site. The critical magnetic fluctuations accompanying the
QCPs are at the origin of Cooper-pairing.
*This work was supported by the Czech Science Foundation (GAČR) Grant No. 18-23606S,
the EU COST Action CA16218 and by the Czech Ministry of Education under the COST
project scheme, project No. LTC18024.
[1] J. Prokleška et al., Phys. Rev. B 92, 161114(R) (2015).
[2] S. Kambe et al., Phys. Rev B. 101, 081103(R) (2020).

Speaker: Custers J. (Faculty of Mathematics and Physics, Charles University, Prague)

Parallel sessions: částicová fyzika - CERN

128 Novel high-luminosity fixed-target experiment at the LHC

Extraction of the multi-TeV proton and lead LHC beams with a bent crystal or by using an
internal gas target allows one to perform the most energetic fixed-target experiment ever. pp,
and pA collisions at collision energy of 115 GeV and Pbp and PbA collisions at 72 GeV can
be studied with high precision and modern techniques over a broad rapidity range. Using the
LHCb and ALICE detectors in a fixed-target mode offers unprecedented possibilities to study,
among others: the quark, gluon and heavy-quark content of the nuclei in the poorly known
region of the high-momentum fractions, heavy-flavour production in a new energy domain,
half way between the SPS and RHIC.
In this talk, the technical solutions to obtain a high-luminosity fixed-target experiment at the
LHC will be reviewed and their possible implementations with the ALICE and LHCb
detectors will be discussed. Projection studies for various observables such as Drell-Yan,
charm, beauty and quarkonium production, with both detector set-ups used and with various
nuclear targets and the LHC lead beams will be presented.

Speaker: Trzeciak B. (Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague)

Trzeciak_AFTER_kcsf20_v2.pdf

129 OTEVŘENÁ DATA LHC EXPERIMENTU ATLAS

Experimenty na největším světovém urychlovači LHC v mezinárodní laboratoři CERN
zaznamenávají velké množství dat ze srážek protonů a těžkých iontů. Tato data jsou ukládána
ve speciálních formátech a procházejí několika kroky zpracování, než jsou vhodná pro
fyzikální analýzu. Část zpracovaných dat byla některými experimenty uvolněna pro všechny
zájemce. Spolu s daty jsou k dispozici i nástroje pro jejich zpracování a detailní dokumentace
postupů a objasnění používaných pojmů. Na veřejně dostupných datech experimentu ATLAS
ukážu možnosti jejich využití pro propagaci oboru i pro verifikaci některých výsledků
nezávislými experty.

Speaker: Chudoba J.

Chudoba.pdf

Chudoba.pptx

130 ALICE ITS Upgrade

The ALICE Inner Tracking System detector is undergoing a major upgrade in order to cope
with the increased data rates and to meet the requirements as set out by the physics goals of
the experiment after Long Shutdown 2. The new ITS will be completely made up of ALPIDE
monolithic active pixel sensors based on a CMOS 180nm process. A single sensor measures
15mm x 30mm and contains half a million pixels distributed over 512 rows and 1024
columns. These 50um thick sensors, with 27um x 29um pixel pitch, are mounted on ultra-
lightweight carbon composite support structures with an embedded cooling system. This
results in a considerable reduction of the material budget (down to 0.35% X_0 for the inner
layers and ∼1% X_0 for the outer layers) and a significant improvement of the impact
parameter resolution and tracking efficiency. The innermost ITS layer will be moved as close
as 23mm to the interaction point. The integration of the ITS detector assembly, made of the
three innermost and four outermost layers, has been almost completed and the
commissioning, first in the laboratory, is ongoing. The detector will be installed in ALICE in
2020. This talk will give a brief overview of the motivation for the upgrade and will present
the first results of the detector performance obtained during the commissioning.

Speaker: Isakov A. (Nuclear Physics Institute of the CAS, Řež)

ITS_upgrade_ver4.pdf

131 OPEN CHARM AND CHARM-TAGGED JETS PRODUCTION WITH ALICE AT LHC

Charm quarks are mostly produced in hard partonic scattering processes in the early stages of
a heavy-ion collision, before the quark-gluon plasma (QGP) is formed. Because of their large
mass the production cross section can be calculated using perturbative quantum
chromodynamics down to zero transverse momentum. Therefore, they are ideal probes of the
properties of this hot, dense, and strongly interacting medium.
Measurements of heavy-flavour tagged jets bring more relevant information of the initial
parton kinematics than traditional hadron measurements and can provide information on
heavy-quark energy loss in the QGP, in particular on how the radiated energy is dissipated in
the medium. Moreover, the study of charm-baryon production in heavy-ion collisions
provides unique information on hadronization mechanism.
This talk focuses on the latest results of charm-tagged jets and open charm production with
the ALICE detector at the LHC.

Speaker: Kvapil J. (University of Birmingham, UK)

openCharmProdAtAlice_JKvapil_v5.pdf

Plenary Talks: fyzika pevných látek

132 Highlights in physics of two-dimensional crystals through cryomagnetic optics

The discovery of graphene – the archetype two-dimensional (2D) system, stimulated the
frantic pace of research in the area of 2D materials (2DM). The rapid progress of the field,
particularly in the growth technologies, is enabling expanding the research interests in other
2DM with outstanding optical, transport, magnetic and other properties giving rise to a
plethora of tailored functionalities. Looking beyond the flatland, the 2D slabs can also be
reassembled into designer heterostructures made layer by layer in a precisely chosen
sequence. Such heterostructures (often referred to as ‘van der Waals’) reveal unusual
properties driven by the stacking and mutual orientation of the 2D building blocks. In my talk,
I will review the current state of knowledge on the most topical areas of 2DM research. First,
the stacking phenomenon responsible for numerous exotic states ranging from
superconductivity to Mott metal-insulator transition will be discussed. Next, the phenomenon
of 2D magnetism will be revisited and I will review the limits imposed on boosting the
material’s properties given by the Mermin–Wagner theorem. Finally, several recent
experimental reports will be highlighted and future prospects in the field of 2DM will be
outlined.

Speaker: Vejpravová J. (Department of condensed matter physics, Faculty of mathematics and physics, Charles University, Prague)

Kalbacova-Vejpravova.pdf

Kalbacova-Vejpravova.pptx

133 Conference closing

Surprise for the persistent individuals - goodbye drink
(foyer of building A - behind the lecture room T1)

Príspevky do zborníku.pdf

134 Surprise for the persistent individuals - goodbye drink