Antihydrogen is an exciting system to perform tests of fundamental physics by comparing it with its matter counterpart: hydrogen. One of the most interesting transitions for such comparisons is the 1S-2S, since it has been measured with an extraordinary precision in hydrogen [1]. Over the last decades, the development of production and trapping techniques for antihydrogen [2] has enabled...
The BASE collaboration performs high-precision Penning trap measurements of the g-factors and charge-to-mass ratios of the proton and antiproton to test CPT in the baryonic sector [1]. Currently, the g-factor measurement of the proton is limited by the statistical uncertainty. This uncertainty stems from finite particle temperatures, which were so far restricted to about 1K by the technique of...
Pairing integrated photonics with surface-electrode ion traps is an emerging technology, potentially opening the way to build novel architectures for quantum information processing [1, 2, 3]. Other than solving the scalability issues presented by individual addressing of multiple ions with free-space laser setups, it allows engineering the optical fields coupled to the ions and hence...
Free-space optical lattices are ubiquitous in atomic physics and are often employed for creating spin-dependent forces used for entangling gate operations and neutral atom trapping. Recently, there has been an interest in gaining control over the absolute phase of the optical lattice [1] and harnessing it for applications in quantum metrology, quantum information processing with continuous...
In trapped-ion systems, the majority of entangling operations are implemented in the adiabatic regime [1,2]. Adiabatic in this context means that we can selectively excite a single set of terms in the Lamb-Dicke expansion and are able to neglect the remaining off-resonant terms. Then only a single motional mode (with secular frequency $\nu$) participates in the interaction. This is possible if...
The study of exotic nuclei far from the valley of stability provides basic information for a better understanding of nuclear structure and the synthesis of the elements in the universe. It is of special interest to probe the edges of stability with their unexpected and novel properties. The nucleus $^{100}$Sn is the heaviest self-conjugate doubly-magic nucleus in the chart of nuclides, and...
Type I X-ray bursts occur at astrophysical sites where a neutron star accretes H/He-rich matter from a companion star, leading to nuclear burning on the neutron star surface. The only observable is the X-ray burst light curve, which is used as a unique diagnostic of the outer layers of accreting neutron stars such the accretion rate and fuel composition. In addition to the astrophysical...
Recent technical developments and experimental results from the ISOLTRAP mass spectrometer at ISOLDE/CERN will be presented in this contribution. During CERN’s Long Shutdown 2 (LS2), a large variety of technical upgrades and maintenance work have been performed. Most significantly, a new offline reference ion source has been built and commissioned, combining a surface ion source and a laser...
High-precision mass measurements are essential for understanding the structure of exotic nuclei. These measurements serve as excellent tests of the latest nuclear models and provide key inputs for calculations in nuclear astrophysics. Light nuclei at the limits of nuclear binding are particularly important, as they are accessible with various ab-initio models, and so provide good tests for how...
The increasing complexity of trapped-ion experiments requires more powerful classical control systems, in particular to work with many channels in parallel. I will present work on extending our in-house developed control system which is used on multiple setups across several research groups [1-3]. The latest development cycle is focused on the increased requirements of multi-channel,...
At the Ion Traps and Lasers Laboratory of the University of Granada we have built a linear Paul trap apparatus as an assisted ion-trap system for a high-magnetic-field Penning trap experiment. The goal of this experiment is to generate and manipulate a qubit via the “clock” S1/2 -> D5/2 transition of 40Ca+ to read out motional frequencies of a 40Ca+ - 40Ca+ crystal in the ground state of...
We present progress on our experimental setup where we will use novel optical tweezers – derived from spatial light modulators – to manipulate the phonon spectrum of a two-dimensional ion crystal in a Paul trap [1]. This allows us to control the effective spin-spin interactions between the ions in order to realize and study various Hamiltonians of interest [2]. In particular, the pinning of a...
It is widely known that in a classical quadrupole Paul trap with endcap electrodes the localization of the particles with the narrow-defined charge to mass ratio realizes at fixed power supply parameters. If we consider a Coulomb crystal in a classical Paul trap, one can see the radial splitting of the crystal associated with the effective potential form at different voltages on the rod and...
Trapped ions in RF traps are a well-established platform for analog and variational quantum simulation of quantum many-body systems. Up to now, ions in linear Paul traps allow for simulations of the 1D Ising model with up to 50 spins. In our project, we aim for extending this approach to the second dimension which will enable studies of 2D spin models with a larger particle number. Our new ion...
The quantum properties underlying a wide range of natural materials, such as topological matter or interesting molecules, have proven too complex to understand using classical physics and standard computation. The field of digital quantum simulation has been developed in order to study the behaviour of quantum systems by replicating the energy dynamics in a controlled, gate-based manner. The...
Abstract:
Quantum technologies employing trapped ion qubits are currently some of the most advanced systems with regards to experimental methods in quantum computation, simulation and metrology. This is primarily due to the excellent control available over the ion’s motional and electronic states. By treating the ions as composite quantum systems, with qubit states that can be addressed by...
High precision experiments using muons (μ+) and muonium atoms (μ+e−) offer promising opportunities to test theoretical predictions of the Standard Model in a second-generation, fully-leptonic environment. Such experiments including the measurement of the muon g-2, muonium spectroscopy and muonium gravity would benefit from intense high-quality and low-energy muon beams.
At the Paul...
The BASE collaboration at the antiproton decelerator facility of CERN conducts antiproton g-factor and charge-to-mass ratio measurements with precisions on the parts per billion to parts per trillion level respectively. So far, we have measured the antiproton g-factor to 1.5 ppb and the antiproton’s charge-to-mass ratio to 69 ppt respectively [Smorra et al. 2017, Ulmer et.al. 2015]....
The ERC Project STE$\bar{P}$, "Symmetry Tests in Experiments with Portable Antiprotons", targets the development of transportable antiproton traps to enhance the sensitivity of CPT invariance tests with antiprotons that are conducted in the BASE collaboration. To enable antiproton measurements with improved precision, we are commissioning the transportable trap system BASE-STE$\bar{P}$ in the...
The ERC project STEP ”Symmetry Tests in Experiments with Portable Antiprotons“ is building a transportable antiproton trap BASE-STEP to relocate antiproton precision measurements and ultimately improve the limits of the measurement precision of CPT invariance tests comparing the fundamental properties of protons and antiprotons. Recently, the BASE collaboration ”Baryon Anti-baryon Symmetry...
Antihydrogen is one of the most simple pure antimatter bound states, which can be synthesised and trapped for extended periods of time by the ALPHA collaboration since 2010 [1]. A consequence of CPT symmetry is that antimatter bound states will present the same energy spectrum as their matter equivalents, and over the last five years ALPHA have measured antihydrogen transitions as a direct...
We develop an experiment to study the energy exchange during the sympathetic cooling of a light ion, 9Be+, by a set of laser-cooled heavy ions, 88Sr+. The objective is to simulate an important step of the GBAR (Gravitational Behavior of Antihydrogen at Rest) experiment installed at CERN which aims at studying the effect of the Earth's gravity on anti-matter by analyzing the free fall of...
The 1S-2P transition has been measured to a precision of $5\times 10^{-8}$ in 2018 by the ALPHA collaboration[1]. This milestone was achieved by allowing a trappable 2P state to decay to a non-trappable 1S state causing it to annihilate with the inner wall of the trapping apparatus. The annihilation events were destructively measured using a silicon vertex detector. The next generation ALPHA-3...
Antiprotons created by laser ionization of antihydrogen are observed to quickly escape the ALPHA trap. Further, positron plasmas heat more quickly after the trap is illuminated by laser light for several hours. These unexpected phenomena are caused by patch potentials - variations in the electrical potential along metal surfaces. A simple model for the effects of patch potentials explains the...
Precision measurements on antihydrogen allow for testing CPT symmetry. The ALPHA Collaboration at CERN performs laser spectroscopy of antihydrogen in a magnetic minimum trap in order to compare its energy level structure to that of hydrogen [1, 2, 3]. Antihydrogen atoms are produced by three-body recombination of an antiproton and two positrons [4]. Antiprotons are provided in the form of a...
The antiProton Unstable Matter Annihilation experiment (PUMA) is aimed at investigating nuclear haloes and neutron skins, that short-lived nuclei can exhibit [1]. Antiprotons are especially suited for this investigation as they probe the outermost tail of the nuclear density distribution [2]. When antiprotons and nuclei are brought together with low relative kinetic energies, an antiproton can...
The BASE collaboration at the antiproton decelerator facility of CERN is testing the Standard Model by comparing the fundamental properties of protons and antiprotons at lowest energies and with highest precision. Several world-record measurements have been performed in BASE such as the comparison of the antiproton-to-proton charge-to-mass ratio with a fractional precision of 69 parts per...
The Antihydrogen Laser Physics Apparatus (ALPHA) is based at the European Centre for
Nuclear Research (CERN) antiproton decelerator facility. Using low energy antiprotons we
produce, trap, and study the bound state of an antiproton and positron, antihydrogen [1].
Given the long history of atomic physics experiments with hydrogen, spectroscopy
experiments with antihydrogen offer some of...
A novel radio-frequency (RF) ion trap based on planar printed-circuit board (PCB) electrodes was designed and simulated. This device would serve as a commercial ion cooler and buncher that delivers a low emittance ion bunch to laser spectroscopy experiments, such as the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment in ISOLDE at CERN.
The ions inside the trap were cooled by...
Highly charged ions are a great platform to test fundamental physics in strong electric fields. The field-strength experienced by a single electron bound to a high Z nucleus reaches strengths exceeding 1018V/m. Perturbed by the strong field, the g factor of a bound electron is a sensitive tool that can be both calculated and measured to high accuracy. In the recent past, g factor...
The antiProton Unstable Matter Annihilation (PUMA) project aims at investigating the nucleon composition in the matter density tail of short-lived as well as stable isotopes by studying antiproton-nucleon annihilation processes. For this purpose, low-energy antiprotons provided by the Extra Low Energy Antiproton (ELENA) facility at CERN will be trapped together with the ions under...
Nuclear moments have proved to be excellent probes for nuclear configurations and thus act as excellent benchmarks for nuclear theory. The magnetic octupole moment, which has for now only been measured for 19 stable isotopes, is very promising for the study of magnetization currents and the distribution of nucleons. We present the construction of the ACORN (Alkali-earth ions Confined for...
Here we described a compact penning trapped ion system. The traditional superconducting magnet is changed into permanent magnet. We did a simulation about the magnet system and the magnetic field uniformity is simulated. Experiment are under developing to measure the magnetic field uniformity. The penning trap geometry is also designed to compatible with the magnet. Laser cooling technic...
High resolution spectroscopy of molecules is a prime candidate to measure potential temporal changes in the proton-to-electron mass ratio, μ [1]. These potential changes can be detected by comparing vibrational or rotational transitions in molecules to optical atomic transitions.
In our experiment, a vibrational Raman transition in a nitrogen ion will be compared to a quadrupole transition...
Different neutral and charged interstellar molecules constitute the building blocks for a rich reaction network in the interstellar medium (ISM). Many complex molecules have been detected but many observed spectra still have unidentified features. The abundance of negative ions in the ISM and their role in the chemistry of these environments has been subject to long-standing discussions in...
Recent studies suggest that the pharmacological activity of biomolecular drugs associates with their gas-phase geometries but not with the aqueous-phase structures [1]. In this scenario, the gas-phase study of biomolecules becomes more relevant with emerging RNA and DNA-based drugs by contributing knowledge to their biologically active geometry. 2’-deoxyadenosine-5’- monophosphate(dAMP) is a...
Precision spectroscopy on trapped ions subject to correlated dephasing can reveal a multitude of information in the absence of any single-particle coherences. We present measurements of ion-ion distances, transition frequency shifts and single-shot measurements of laser-ion detunings by analyzing multi-particle correlations in linear and planar Coulomb crystals of up to 91 ions. We show that...
The ARTEMIS (AsymmetRic Trap for the measurement of Electron Magnetic moment in IonS) [1] experiment at the HITRAP facility in GSI, Darmstadt, aims to measure magnetic moment of the electron bound to highly charged ions using the laser-microwave double-resonance spectroscopy [2] technique. The ARTEMIS Penning trap consists of two parts, the creation part of the trap which allows for in-situ...
We present the first observation of Feshbach resonances between neutral atoms and ions. [1,2] While Feshbach resonances are commonly utilized in neutral atom experiments, however, reaching the ultracold regime in hybrid traps is challenging, as the driven motion of the ion by the rf trap limits the achievable collision energy. [3] We report three-body collisions between neutral 6Li and 138Ba+,...
Trapped Rydberg ions are a novel approach to quantum information processing [1, 2]. This idea combines qubit rotations in the ions' ground states with entanglement operations via the Rydberg interaction [3]. Importantly, the combination of quantum operations in ground and Rydberg states requires the Rydberg excitation to be controlled coherently. In the experiments presented ...
The upcoming revolution in computation - quantum computing - will open up new avenues to efficiently solve classically hard problems, like quantum simulation and optimization tasks. A leading implementation of a feasible quantum processor is realized by trapped ions, where electronic states in stored ions represent physical quantum bits (qubits) [1]. The microfabrication of ion traps [2, 3] is...
We present a theoretical analysis of optimisation of detection efficiency of optical signal scattered from dipole emitters using a far-field interference. These calculations are motivated by previous experimental demonstrations of coherent interaction of light with long strings of trapped ions [1,2,3]. For our models, we consider an ion string containing up to 10 ions, stored and laser cooled...
The field of quantum computing with trapped ions has seen many milestone achievements, the challenge for the future lies in scaling ion processors to qubit numbers capable of tackling interesting problems – without forgoing the high fidelities seen in smaller prototypes. One class of large-scale ion trapping architecture comprises dedicated regions for trapping, measurement, storage and...
Trapped ions have proved to be a promising way of realising a large-scale quantum computer, due to their long coherence times and reproducibility, while also allowing for modular architectures which is key for a scalable, universal quantum computer. A blueprint for a trapped-ion based quantum computer outlines operating with global microwave fields to dress the ground-state hyperfine manifold...
In the framework of blind quantum computing, quantum computations can be delegated to an untrusted server while ensuring privacy and verifying their correctness [1]. For an experimental demonstration, we consider the practical case of measurement-based blind quantum computation (MBBQC) on a continuously rebuilding cluster state. This protocol involves sequential measurements and remote state...
Quantum thermodynamics focuses on extending the notions of heat and work to microscopic systems, where the concepts of non-commutativity and measurement back-action play a role [1]. Our experimental system consists of one or multiple qubits implemented in the Zeeman sublevels of the ground electronic state of 40Ca+, and the ion register is held in a microstructured Paul trap [2]. Quantum logic...
Entangling gates are arguably the main ingredient of quantum information processing (QIP). Trapped ion systems have typically outshone other quantum hardware in preparing Bell states. Two ion entanglement has been extensively covered [1, 2, 3] and sequences of pairwise gates can be used to generate multipartite entanglement. Alternatively, global irradiation is faster, which is important as...
Single ion addressing provides a critical computational advantage for trapped-ion registers used for large-scale quantum simulation and computation [1][2]. Several schemes are currently used including arrays of mechanically positioned micro-optic fibers [3], holographic diffraction patterns produced by arrays of micromirrors [4], and beam splitting by AODs driven by multi-tone rf frequencies...
A major architecture for large-scale quantum computing with trapped ions relies on individual computational nodes that are linked via quantum networking. This multi-node architecture would also benefit hybrid networks between trapped ions and other quantum systems. Quantum networks of practical scales will require modularization of the quantum control hardware and reduction of the equipment...
Generation and manipulation of non-classical states of motion has been of interest with motivation in quantum metrology, quantum enhanced sensing [1] and quantum thermodynamics. Fock states of motion with exactly defined discrete value of energy are experimentally achievable realizations of such non-classical states in ion trap. Although the significant progress in the Fock state preparation...
In 1995, Zoller [1] suggested the realization of a quantum computer by means of using ions in a linear trap. Since linear traps are only capable of storing a few tens of ions, the transition to 2D surface traps will be essential for useful quantum computers. Hence, plentiful research was done already about micro-fabricated 2D surface traps in an industrial environment [2,3,4]. To pave the way...
Abstract
Rydberg ions have large dipole and quadrupole polarizabilities which makes them extremely sensitive to external electric fields[1][2]. As a result, an ion in the Rydberg state experiences altered trapping potential which leads to motion-dependent Rydberg excitation energies[3]. Higher the Rydberg state more is the sensitivity to the electric quadrupole trapping fields. The...
Quantum computers have the potential to revolutionize computation by making
certain types of classically intractable problems solvable. There are several
platforms, that might host a future quantum computer. Trapped ions enable
quantum gate operations on quantum bits (qubits) by manipulating single or
multiple ions. Trapped ion quantum computing offers advantages over other
platforms like...
The number of qubits in quantum computing architectures must be increased dramatically in order to demonstrate an advantage over classical hardware [1]. This “scaling up” must be performed without experiencing reductions in the rate, or the fidelity of the qubit operations. Multiple ions can be confined within a single ion trap. However, qubit gate times and the motional mode density scale...
Ion traps and their geometry have seen their complexity increase for several years. Examples of this trend are the integration of waveguides, photodetectors [1] and the design of array of trap [2][3][4]. To continue in this path, significant challenges for electric signal delivery must be solved. I will present a functional trap using Through Silicon Vias (TSV) electrodes connection (both...
The Ion Quantum Technology group has proposed a scalable quantum computing design made up of modular surface ion traps which slot together. One of the main challenges in realizing this design is demonstrating fault-tolerant error correction on a surface trap. We use an X-junction trap which has designated zones for trapping, performing quantum gates and reading out results. It uses surface...
Single-qubit rotation operations and two-qubit entangling gates form a universal set of quantum operations capable of performing any quantum algorithm. Here, we consider the implementation of single- and two-qubit gates using microwaves as a scalable alternative to the more widely used laser-based addressing techniques, which have fidelities that are typically limited by photon scattering [1]....
The complexity and variety of molecules offer opportunities for metrology and quantum information that go beyond what is possible with atomic systems. The hydrogen molecular ion is the simplest of all molecules and can thus be calculated ab initio to very high precision [1]. Combined with spectroscopy this allows to determine fundamental constants and test fundamental theory at record...
The 1S-2S transition of hydrogenic systems is a benchmark for tests of fundamental physics [1]. The most prominent example is the 1S-2S transition in atomic hydrogen, where impressive relative accuracies have been achieved [2-3]. Nowadays, these fundamental physics tests are hampered by estimates of uncalculated higher-order QED terms and the uncertainties in the fundamental constants required...
A novel Penning-trap mass spectrometry technique based on optical detection is under development at the University of Granada. This technique is universal, non-destructive, and single ion-sensitive. The scattered photons by a $^{40}$Ca$^{+}$ ion will be used to measure the normal mode eigenfrequencies of the unbalanced crystal formed by this ion and a target one [1] when the crystal is cooled...
A significant contribution to the uncertainty budgets of optical clocks based on the $^{171}\text{Yb}^{+}$ $S_{1/2}$ $\rightarrow$ $F_{7/2}$ electric octupole (E3) transition results from the Stark shift induced by black-body radiation (BBR) of the environment of the trapped ion. Even if precise knowledge on the thermal environment is available, uncertainty in the sensitivity of the shift to...
We investigate scalable surface ion traps for quantum simulation and quantum computing. We have developed a microfabricated surface trap consisting of two parallel linear trap arrays with 11 trapping sites each. The trap design requires two interconnected metal layers to address the island-like DC electrodes and a third to shield the substrate.
The trap fabrication is carried out by...
A future quantum computer will potentially outperform a classical computer in certain tasks, such
as factorizing large numbers [1]. A promising platform to implement a quantum computer are trapped
ions, as long coherence time, high fidelity quantum logic gates and the implementation of quantum
algorithms, such as the shore algorithm, have been demonstrated [2], [3]. To evolve trapped...
The Antihydrogen Laser Physics Apparatus (ALPHA) collaboration at CERN has been successfully pushing the boundaries of high precision atomic physics with antihydrogen to characterise the peculiarities of antimatter in a universe suspiciously dominated by matter today. Starting from the blossoming expertise developed by the collaboration with antihydrogen traps and laser spectroscopy...
The ASACUSA experiment aims to perform a ppm measurement of the ground-state hyperfine structure of antihydrogen using a spin-polarized antihydrogen beam. The production of antihydrogen in the mixing trap, the so-called Cusp trap – due to its cusped magnetic field – is done by merging positron and antiproton plasmas. To produce a sufficient amount of ground-state antihydrogen it is crucial to...
Hydrogen remains the go-to tool for testing fundamental physics, with the recent proton radius puzzle being a prime example. Here, I present a novel scheme for producing ultracold atomic hydrogen, based on threshold photodissociation of the BaH+ molecular ion. BaH+ can be sympathetically cooled using laser cooled Ba+ in an ion trap, before photodissociating it on the single photon A1Σ+←X1Σ+...
Antihydrogen atoms can be formed via three body recombination of antiprotons and positrons. The ASACUSA collaboration will use this technique of forming atoms in order to perform a ppm measurement of the ground-state hyperfine structure of them.
A proton source was developed such that hydrogen can be produced using the same apparatus and techniques which are used in the antimatter...
The detection of the double-beta decay mode which would reveal the nature of the neutrino, Dirac or Majorana, is an extremely rare event where two emitted electrons share all the available energy of the decay and no neutrino is emitted. The current experiments in the search of such decay mode are far from a background-free condition, and the level of background achieved plays a crucial role in...
The Multi Ion Reflection Apparatus for Collinear Laser Spectroscopy (MIRACLS) represents a new approach for precision measurements of nuclear ground-state properties in short-lived radionuclides. Conventional Collinear Laser Spectroscopy (CLS) [1-3] requires ion yields of more than 100-10000 ions per second, depending on the element, delivered from a radioactive ion beam (RIB) facility to...
Ever since its introduction in the mid 1970s, laser cooling has become a fundamental technique to prepare and control ions and atoms for a wide range of precision experiments.
In the realm of rare isotope science, for instance, specific atom species of short-lived radionuclides have been laser-cooled for fundamental-symmetries studies [1] or for measurements of hyperfine-structure constants...
Study on exotic nuclei has become one of the research frontiers in nuclear physics. They can be produced by bombarding an energetic (MeV~GeV) projectile onto a target. Among various products, the ions of interest can be promptly and efficiently selected by in-flight separation. To precisely measure their properties, it is preferable to couple a low-energy (eV~keV) experimental terminal to the...
Research groups in a wide range of disciplines at the Leibniz Universität Hannover, the Physikalisch-Technische Bundesanstalt (PTB) Braunschweig, and the Technische Universität Braunschweig are working together in the newly-created Quantum Valley Lower Saxony to create a trapped-ion quantum computer with fully interconnected qubits. A pair of existing trapped-ion experiments, one at LUH and...
Trapped ions are a leading platform for quantum computing due to the long coherence time, high-level of control of internal and external degrees of freedom, and the natural full connectivity between qubits. Single and multi-qubit operations have been performed with high fidelity (>99.9%), which has enabled the demonstration of small universal quantum computers (∼10 atoms). However, scaling...
Private communication over shared network infrastructure is of fundamental importance to the modern world. In classical cryptography, shared secrets cannot be created with unconditional security; real-world key exchange protocols rely on computational conjectures such as the hardness of prime factorisation to provide security against eavesdropping attacks. Quantum theory, however, promises...
Trapped atomic ions are one of the most promising quantum computing architectures. They exhibit all of the primitives necessary for building a quantum computer and have very few fundamental limitations to the achievable gate fidelities. While high-fidelity quantum logic has already been demonstrated on a small number of qubits, scaling up the system without compromising its...
Laser cooled and trapped atomic ions are promising platforms for quantum networking, sensing, and information processing because they are quantum systems well isolated from their surrounding environment. The species and isotope selected for trapping have different properties. Nuclear spin $I=\frac{1}{2}$ isotopes have long coherence times for a ground-state hyperfine qubit with robust...
In this introduction session to COMSOL Multiphysics® software you will get an overview of COMSOL® capabilities in modeling electromagnetic fields and the motion of particles therein.
In Unit 1 we will cover the basic modeling workflow for modeling stationary and time-dependent low frequency EM fields such as capacitive, resistive and inductive systems.
Unit 2 will give you an introduction...
