Quantum Information in Spain ICE-8

Contribution List

119. Quantum randomness, cryptography and imaging: from lab to industry

Valerio Pruneri (ICFO)

29/05/2023, 09:30

Session 4.1

In the talk I will present examples of projects which have leveraged fundamental quantum physics for developing technologies that have gone into products for cybersecurity, large-scale computation and biological detection

38. Fully passive quantum key distribution

Víctor Zapatero (Vigo Quantum Communication Center)

29/05/2023, 10:20

Talk

Session 4.1

In recent years, quantum key distribution (QKD) has become a fully fledged application of quantum information science, and QKD services are being supplied by different companies/institutions around the world. However, the practical security of QKD is not well-established yet, mainly due to the difficulty of guaranteeing that real QKD implementations stick to the assumptions and models on which...

120. KeySight

Benjamín García (KEYSIGHT TECHNOLOGIES SPAIN), Miguel Ángel Fernández (KEYSIGHT TECHNOLOGIES SPAIN)

29/05/2023, 11:20

Session 4.2

61. Fast single-photon detectors and real-time key distillation enable high secret-key-rate quantum key distribution systems

Dr Fadri Gruenenfelder (University of Vigo)

29/05/2023, 11:40

Talk

Session 4.2

We implemented a simplified time-bin BB84 quantum key distribution protocol with the purpose of achieving the highest possible secret key rate at short distances. The sender Alice emits signals at a rate of 2.5 GHz. In the key-generating basis, we use a superconducting nanowire single photon detector (SNSPD) with a novel design optimized for fast count rates. The in-house designed and...

58. Distributing circuits over heterogeneous, modular quantum computing network architectures

Pablo Andres-Martinez (Quantinuum)

29/05/2023, 12:00

Talk

Session 4.2

We consider a heterogeneous network of quantum computing modules, sparsely connected via Bell states. Operations across these connections constitute a computational bottleneck and they are likely to add more noise to the computation than operations performed within a module. We introduce several techniques for transforming a given quantum circuit into one implementable on a network of the...

54. Topologically robust network nonlocality

Tamás Kriváchy (TU Wien)

29/05/2023, 12:20

Talk

Session 4.2

In recent years, the study of Bell-type nonlocality on networks has led to an array of intriguing foundational results. Nonetheless the field still faces difficulties in finding a justified application. One of the key barriers for this is the assumption of independent sources in network nonlocality, which is difficult to enforce. In our work we examine a possible operational interpretation for...

41. Guaranteeing non-classicality in experimental quantum networks without assuming quantum mechanics

Alejandro Pozas-Kerstjens (Institute of Mathematical Sciences (ICMAT-CSIC))

29/05/2023, 12:40

Talk

Session 4.2

Quantum technologies promise interesting new approaches to areas such as computing and communication. A branch that is becoming increasingly interesting is that of quantum networks. The technological assets for quantum networks have been developing rapidly in recent years and many implementations, often geared towards quantum cryptography, have been reported. In order to demonstrate security...

113. Inertial sensing using matter-wave interferometry

Prof. Dennis Schlippert (1Leibniz Universität Hannover, Institut für Quantenoptik)

29/05/2023, 14:20

Invited

Session 4.3

In a Mach-Zehnder-type light pulse atom interferometer, matter waves are split, mirrored, and recombined using coherent atom optics. With the leading order phase shift scaling with the enclosed space-time area, the momentum transfer induced by the atom optics light pulses as well as the free evolution time are key to significantly enhanced sensitivity to inertial forces and motivate...

47. Security of discrete-modulated continuous-variable quantum key distribution

Mr Carlos Pascual (ICFO)

29/05/2023, 15:10

Talk

Session 4.3

Continuous variable quantum key distribution with discrete modulation has the potential to provide unconditional security using widely available optical elements and existing telecom infrastructure, while allowing for the use of well studied error correction protocols. However, proving finite-size security against coherent attacks poses a challenge. In this work we apply the entropy...

14. Activation of metrologically useful genuine multipartite entanglement

Róbert Trényi (Universidad del País Vasco)

29/05/2023, 15:30

Talk

Session 4.3

In quantum metrology, the usefulness of a quantum state is determined by how much it outperforms separable states. For the maximal metrological usefulness genuine multipartite entanglement (GME) is required. In order to improve the usefulness of a quantum state we consider a scheme of having several of its copies. With this scheme, it is possible to find a large class of practically important...

75. Quantum systems for enhanced detectors for High Energy Particle Physics

Georgy Kornakov (Warsaw University of Technology (PL))

29/05/2023, 16:20

Poster

Session 3.4

In this contribution I will present ideas and ongoing project to enhance the capabilities of particle detectors using quantum systems [1]. The presented technologies could not only improve the accuracy of measurements but also provide a new dimension by directly sensing properties as spin of individual particles. The level of maturity and applicability of ideas range from those already proved...

18. Neural-network-assisted quantum magnetometers

Dr Yue Ban (TECNALIA)

29/05/2023, 16:40

Talk

Session 3.4

As important branches in quantum technologies, quantum sensing and quantum metrology have experienced significant progress, placing themselves at the forefront of the new generation of technologies harnessing quantum effects. In this presentation, different quantum magnetometers assisted by neural networks are introduced. Our results show that neural networks are valuable in distinct quantum...

86. Nuclear decoupling techniques at the microscale

Carlos Munuera Javaloy (Universidad del País Vasco / EHU Quantum Center)

29/05/2023, 17:00

quantum metrology and sensing

Talk

Session 3.4

We present a method to identify energy shifts which contain structural information in solid-state systems using Nitrogen-Vacancy (NV) centers combined with synchronization techniques. To achieve this, we have developed a theory for Lee-Goldburg based decoupling schemes in microscale-NMR scenarios with NV centers at large static magnetic fields. The introduced RF fields serve two purposes: (i)...

121. Exploring quantum spin models with Rydberg atom arrays

Daniel Barredo

30/05/2023, 09:00

Session 3.1

Rydberg atoms in arrays of optical tweezers offer a new perspective for quantum simulation of many body problems. In this talk, I will give a brief overview about this platform and describe our efforts to control Rydberg interactions to explore different types of spin Hamiltonians. I will report on our recent implementations of the 2D Ising Hamiltonian [1] and the dipolar XY model [2] with...

22. Quantum metrology with non-Gaussian spin states

Manuel Gessner (Universidad de Valencia, IFIC)

30/05/2023, 09:50

Talk

Session 3.1

The well-known spin squeezing coefficient efficiently quantifies the sensitivity and entanglement of Gaussian states [1,2]. However, this coefficient is insufficient to characterize the much wider class of non-Gaussian quantum states that can generate even larger sensitivity gains. In this talk, we present a non-Gaussian extension of spin squeezing based on reduced variances of nonlinear...

5. Bounding the Minimum Time of a Quantum Measurement

Federico Centrone

30/05/2023, 10:20

Talk

Session 3.1

Measurements take a singular role in quantum theory. While they are often idealized as an instantaneous process, this is in conflict with all other physical processes in nature. Here, we adopt a standpoint where the interaction with an environment is a crucial ingredient for the occurrence of a measurement. Within this framework, we derive a general lower bound on the time needed for a...

122. Quantum Computing at FUJITSU

Juan Antonio García Carrasco

30/05/2023, 11:20

Session 4.2

27. Using high-dimensional entanglement for closing the detection loophole in Bell experiments

Adán Cabello

30/05/2023, 11:40

Talk

Session 4.2

I present two approaches for closing the detection loophole in Bell experiments. Both exploit that high-dimensional entanglement allows for loophole-free experiments with low detection efficiency.

The "penalized N-product Bell inequalities" [1] is a method for, starting from any qudit-qudit correlation violating a Bell inequality with a certain critical detection efficiency, identifying...

80. Number-phase uncertainty relations and bipartite entanglement detection in spin ensembles

Geza Toth (University of the Basque Country UPV/EHU)

30/05/2023, 12:00

Talk

Session 4.2

We present a method to detect bipartite entanglement based on number-phase-like uncertainty relations in split spin ensembles. First, we derive an uncertainty relation that plays the role of a number-phase uncertainty for spin systems. It is important that the relation is given with well-defined and easily measurable quantities, and that it does not need assuming infinite dimensional systems....

67. Quantum supremacy in mechanical tasks: projectiles, rockets and quantum backflow

Mr David Trillo (IQOQI Vienna)

30/05/2023, 12:20

Talk

Session 4.2

While current research in quantum theory focuses on the exploitation of quantum effects in communication and computation scenarios, quantum systems are also known to be advantageous for some mechanical tasks. The most known effect is that of tunneling, but there are other less well known effects. One of those is quantum backflow [1], a phenomenon in which a free quantum particle with positive...

19. Optimal control of dissipation and work fluctuations for rapidly driven systems

Alberto Rolandi

30/05/2023, 12:40

Talk

Session 4.2

To achieve efficient and reliable control of microscopic systems one should look for driving protocols that mitigate both the average dissipation and stochastic fluctuations in work. This is especially important in fast driving regimes in which the system is driven far out of equilibrium, potentially creating large amounts of unwanted entropy production. Here we characterise these optimal...

123. Making the case for quantum machine learning

Vedran Dunjko (Universidad de Leiden)

30/05/2023, 14:20

Invited

Session 4.3

Quantum machine learning (QML) is often put forward as one of the most likely quantum applications to bring about useful advantages, perhaps even in the near term.
Large-scale quantum computers, once available, will give definite answers to whether this is true, but to make the most out of the significant investments in experimental quantum computing, it is important to try to learn as much...

87. A Fast QKD Prototype Based on Photonic Integrated Circuits

Maria De Matos Afonso Pereira

30/05/2023, 15:10

Talk

Session 4.3

Quantum Key Distribution (QKD) has the potential to play a significant role in improving security in communication networks in the near future. Since the first experimental demonstration [1], multiple QKD experiments have been carried out, the majority of which were proof-of-concept demonstrations that continually broke new records in terms of transmission distance, in both fibre [2,3] and...

9. Taking advantage of noise in quantum reservoir computing

Prof. Florentino Borondo (Universidad Autónoma de Madrid (UAM))

30/05/2023, 15:30

Talk

Session 4.3

The biggest challenge that quantum computing and quantum machine learning are currently facing is the presence of noise in quantum devices. As a result, big efforts have been put into correcting or mitigating the induced errors. But, can these two fields benefit from noise? Surprisingly, we demonstrate that under some circumstances, quantum noise can be used to improve the performance of...

52. How inhomogeneities enhance the manipulability of Ge spin qubits

Jose Carlos Abadillo-Uriel (CEA Grenoble)

30/05/2023, 16:20

Talk

Session 3.4

In recent years, there has been a growing interest in utilizing hole spins in silicon and germanium for quantum information processing. One reason for this is the strong spin-orbit interaction present in the valence band of these materials, which allows for versatile interactions with electric fields. As a result, there have been demonstrations of fast electrical manipulation of hole spin...

91. Multiobjective variational quantum algorithms to solve constrained optimization problems

Pablo Díez Valle (Instituto de Física Fundamental (IFF-CSIC))

30/05/2023, 16:40

Talk

Session 3.4

Combinatorial optimization problems (CO) have a strong impact on a wide range of disciplines such as finance, machine learning, logistics, etc. In addition to finding a solution with minimum cost, problems of high relevance involve a number of constraints that the solution must satisfy. Variational quantum algorithms (VQA) have emerged as promising candidates for solving these problems in the...

11. Simulations of atomic nuclei on a digital quantum computer

Axel Pérez-Obiol

30/05/2023, 17:00

Talk

Session 3.4

We present a variational algorithm to solve ground states of atomic nuclei within the nuclear shell model. The strategy is based on the implementation of ADAPT-VQE, an adaptive version of the variational quantum eigensolver algorithm, on a digital quantum computer. Exact ground energies are found up to medium-mass nuclei by implementing and simulating ADAPT-VQE on quantum circuits using the...

33. Electrical two-qubit gates within a pair of clock-qubit magnetic molecules

Dr Aman Ullah (Instituto de Ciencia Molecular, Universitat de Valencia, Paterna 46980, Spain)

30/05/2023, 17:20

Talk

Session 3.4

Enhanced coherence in HoW$_{10}$ molecular spin qubits has been demonstrated by use of clock-transitions (CTs) . More recently it was shown by some of us that, while operating at the CTs, it was possible to use an electrical field to selectively address HoW$_{10}$ molecules pointing in a given direction, within a crystal that contains two kinds of identical but inversion-related molecules [2]....

13. Easing the experimental requirement for microwave quantum illumination

Dr Roberto Di Candia (Aalto University)

30/05/2023, 17:40

Talk

Session 3.4

Quantum illumination is one of the main paradigms for implementing quantum radar in the low-frequency spectrum. Here, we contribute towards an open-air application of the protocol, by notably easing its experimental requirements. We first define an experimentally feasible receiver for an entangled signal-idler transmitter. This consists in measuring heterodyne the received signal and...

49. Gradient Magnetometry with Atomic Ensembles

Iagoba Apellaniz

30/05/2023, 18:00

Talk

Session 3.4

We calculate precision bounds for estimating the gradient of the magnetic field based on the quantum Fisher information for various types of ensembles, such as for example, a single atomic ensemble with an arbitrary density profile, where the atoms cannot be addressed individually and which is a very relevant case for experiments.

We present a method to find spin states for gradient...

117. Towards large-scale quantum processors based on hole spin qubits

Cécile Yu (QuTech/TU Delft)

31/05/2023, 09:00

Invited

Session 3.1

In recent years, hole spins in silicon and germanium have attracted increasing interest for quantum information processing. In this talk, I will describe recent advances in hole spin qubits for both silicon and germanium towards intermediate- or large-scale quantum processors.
First, I will present the coherent interaction of a hole spin in silicon with a microwave photon. This coupling...

32. Out-of-equilibrium evolution and tensor networks

LUCA TAGLIACOZZO (IFF-CSIC)

31/05/2023, 09:50

Talk

Session 3.1

I will review the recent advances of TN algorithms that allow to compute the out-of-equilibrium dynamics of local observables after a quantum quench and discuss entropies, generalized entropies and coherence of the states generated.

23. Digitized Counter-Diabatic Quantum Algorithms

Dr Xi Chen (University of the Basque Country)

31/05/2023, 10:20

Talk

Session 3.1

Shortcuts to adiabaticity [1] are well-known methods for controlling the quantum dynamics beyond the adiabatic criteria, where counter-diabatic (CD) driving provides a promising means to speed up quantum many-body systems. In this talk, we show the applicability of CD driving to enhance the digitized adiabatic quantum computing paradigm in terms of fidelity and total simulation time. Firstly,...

127. EVIDEN-ATOS

José Camacho

31/05/2023, 11:20

Session 4.2

89. Variational Waveguide-QED Simulators

Cristian Tabares López (Institute of Fundamental Physics (IFF-CSIC))

31/05/2023, 11:40

Talk

Session 4.2

Variational Quantum Algorithms (VQAs) [1] use a classical optimizer to train a parametrized quantum circuit (PQC). These have emerged as a practical way to exploit state-of-the-art quantum computers. Currently, most VQAs have been designed for fully digital approaches, in which the error ends up accumulating for circuits with many parameters. A possible way out is the use of analogue...

124. Quantum Machine Learning in High Energy Physics

Dr Sofia Vallecorsa (CERN)

31/05/2023, 14:20

Session 4.3

Theoretical and algorithmic advances, availability of data, and computing power have opened the door to exceptional perspectives for application of classical Machine Learning in the most diverse fields of science, business and society at large, and notably in High Energy Physics (HEP). In particular, Machine Learning is among the most promising approaches to analyse and understand the data...

34. Photon-magnon interaction in ferromagnets of different sizes

Sergio Martínez-Losa del Rincón

31/05/2023, 15:10

Talk

Session 4.3

We present our first steps towards the coherent coupling between inhomogeneous magnon excitations and resonant photons living in a superconducting cavity. Using a coplanar superconducting transmission line, we perform broad-band ferromagnetic resonance of thin-film mesoscopic magnets. This allows identifying the low-energy Kittel spin-wave excitation (with infinite wavelength). By patterning...

24. Quantum machine learning algorithms and its implementation in molecular qudits

Sebastian Roca-Jerat (Instituto de Nanociencia y Materiales de Aragon)

31/05/2023, 15:30

Talk

Session 4.3

Quantum machine learning (QML) is recently gaining interest in both theory and experiment thanks to variational circuits implemented in the noisy intermediate-scale quantum computers (NISQs) [1]. Since we are in such an era, algorithms capable of being implemented in small circuits are of great interest. In pursuit of this objective, we explore QML algorithms that are implementable in circuits...

55. Evolutionary optimization for Variational Quantum Algorithms

Daniel Faílde (Centro de Supercomputación de Galicia)

31/05/2023, 16:20

Talk

Session 3.4

Variational quantum algorithms (VQAs) are one of the most promising NISQ-era algorithms due to their feasibility for their application in vastly diverse fields. Machine learning, quantum chemistry, mathematics, finance or combinatorial problems can be tackled through VQAs. However, the underlying optimization processes within these algorithms usually deal with local minima and barren plateau...

2. Classical simulation of short-time quantum dynamics

Alvaro Alhambra (IFT - CSIC)

31/05/2023, 16:40

Talk

Session 3.4

Recent progress in the development of quantum technologies has enabled the direct investigation of dynamics of increasingly complex quantum many-body systems. This motivates the study of the complexity of classical algorithms for this problem in order to benchmark quantum simulators and to delineate the regime of quantum advantage. Here we present classical algorithms for approximating the...

105. Efficient quantum simulation of jet evolution in a medium

Wenyang Qian (University of Santiago de Compostela)

31/05/2023, 17:00

Talk

Session 3.4

In recent years, a lot of effort has been put into expanding established jet-quenching formalisms to account for higher-order or energy-suppressed medium-induced effects. Understanding how such contributions emerge is important to have a more complete picture of jet evolution in the medium and to extract more detailed properties of the underlying matter. However, such efforts are in general...

79. High-fidelity ground state preparation for quantum simulations of the two-dimensional Z2 lattice gauge theory

Jesús Cobos Jiménez (Investigador predoctoral)

31/05/2023, 17:20

Talk

Session 3.4

We propose a new variational ansatz for the ground state preparation of the two-dimensional $\mathbb{Z}_2$ lattice gauge theory in digital quantum computers. It is similar to the well known QAOA, but it contains half Trotter step of an imaginary time propagator, which increases the fidelities reached around the phase transition of the gauge theory. We propose a non-probabilistic...

125. Integrating a QC in an HPC environment: the future of quantum accelerators in Italy and Europe

Danniele Ottaviani

01/06/2023, 09:30

Invited

Session 4.1

This talk explores the integration of Quantum Computers (QCs) within High-Performance Computing (HPC) environments and its significance for Italy and Europe. Representing CINECA, the largest Italian supercomputing center and an EuroHPC selected quantum computer hosting entity, we will discuss about the EuroQCS initiative, an European collaboration involving different countries (including...

36. Quantum annealing with superconducting qubits

Pol Forn-Díaz

01/06/2023, 10:20

Talk

Session 4.1

Analog quantum processors hold a high potential to show quantum advantage
in the near future. These systems may be programmed to operate as quantum
annealers to address optimisation problems, as well as variational quantum
algorithms and quantum simulations. The technology to build coherent analog quantum processors is still in a premature stage and requires dedicated efforts to be able to...

4. Tackling thermalization dynamics through decoherent tensor networks

Carlos Ramos Marimón (Universitat de Barcelona)

01/06/2023, 11:20

Talk

Session 4.2

Classical simulation of quantum dynamics from many-body systems with tensor networks is hindered by the exponential growth of entanglement contained at the bonds of a chosen wavefunction factorization (typically Matrix Product States). Modern algorithms try to overcome this entanglement barrier by folding and contracting transversely the network [1], or optimizing schemes to exploit only...

40. Exact solution for quantum strong long-range models using a generalized Hubbard–Stratonovich transformation from cavity QED

Juan Román-Roche (Instituto de Nanociencia y Materiales de Aragón)

01/06/2023, 11:40

Talk

Session 4.2

The field of cavity qed materials seeks to modify the properties of bulk materials by coupling them to an electromagnetic cavity at equilibrium. When the material is, e.g., composed of magnetic dipoles, the resulting system is described by a generalized Dicke model. Under certain conditions, the cavity modes can be traced out, leaving a spin Hamiltonian with cavity-mediated (effective)...

39. Encodings of binary variables for efficient use in a quantum computer

Márcio Taddei (ICFO - The Institute of Photonic Sciences)

01/06/2023, 12:00

Talk

Session 4.2

Quantum computers in the NISQ era (noisy, intermediate-scale, quantum) still offer a relatively small amount of qubits. The largest quantum computers so far, dedicated to binary optimization, do not surpass a few thousands qubits. We nevertheless are willing and able to probe such computers in real-life tasks with their high demand in number of variables to optimize over.
We tackle a binary...

35. Quantum circuits for quantum walks with position-dependent coin operator

Armando Perez (Departamento de Física Teórica & IFIC. Universidad de Valencia/CSIC)

01/06/2023, 12:20

Talk

Session 4.2

Quantum walks (QWs) play an important role in quantum computing. On the one hand, some algoritmical problems can be recast as a QW. On the other hand, many physical phenomena can be simulated with the help of a QW. Here we concentrate on discrete-time QWs, and we discuss quantum circuits that can implement discrete-time quantum walks having an arbitrary position-dependent coin operator [1]....

69. Parallelizing quantum algorithms with classical communication.

Constantino Rodriguez Ramos (CESGA)

01/06/2023, 12:40

Talk

Session 4.2

Hybrid quantum-classical algorithms emerge as one promising approach to improve the performance of current quantum computers. In this work, we consider the method to execute general quantum algorithms on two different QPUs connected via classical communication. The optimal protocol for such computation consists of two steps: First, a quasi-probabilistic simulation scheme generates the required...

126. Quantum simulation with quantum computers, an introduction

Joaquín Fernández-Rossier

01/06/2023, 14:20

Invited

Session 4.3

In this talk I will provide a tutorial introduction to quantum simulation with quantum computers. I will review the failure of conventional computing to address many-body problems and how this prevents progress in many scientific areas. I will discuss whether and how quantum computers, either fault tolerant in the future or noisy intermediate scale state of the art, can help to solve...

29. Quantum reservoir computing in finite dimensions

Rodrigo Martínez-Peña

01/06/2023, 15:10

Poster

Session 4.3

Quantum reservoir computing (QRC) is a machine learning technique where complex quantum systems are exploited to solve temporal tasks, such as predicting chaotic time series and complex spatiotemporal dynamics. Most existing results in the analysis of QRC systems with classical inputs have been obtained using the density matrix formalism. This paper shows that alternative representations can...

73. Fast Pattern Matching in Quantum Circuits

Mr Luca Mondada (University of Oxford, Quantinuum Ltd)

01/06/2023, 15:30

Talk

Session 4.3

Pattern matching of quantum circuits, the task of finding sub-circuits of a quantum circuit that match a given pattern, is an essential tool of quantum circuit compilation. It can be used for instance to find redundant gate sequences that can be rewritten as more efficient computations. We propose an algorithm that performs this task for many patterns simultaneously, independently of the...

99. Low-depth simulations of fermionic systems on realistic quantum hardware

Manuel Algaba (IQM Quantum Computers)

01/06/2023, 15:50

quantum computation and simulation

Talk

Session 4.3

We present a general strategy for mapping fermionic systems to quantum hardware with square qubit connectivity which yields low-depth quantum circuits, counted in the number of native two-qubit fSIM gates. We achieve this by leveraging novel operator decomposition and circuit compression techniques paired with specifically chosen fermion-to-qubit mappings that allow for a high degree of gate...

62. A noisy c-not gate for qudits

Alexandre Orthey (Center for Theoretical Physics, Polish Academy of Sciences)

Poster

Poster Session 1

Weak measurements can give us partial information about the state of a quantum system with a ``partial collapse'' of the wave function. As in every practical measurement, this is done by partially entangling the system of interest with a measurement apparatus, followed by an unavoidable discard of the state of the system. Although the quantum logic gates to perform that on qubits are...

64. A probabilistic perspective for optimizing the parameters of quantum heuristics using evolutionary algorithms

Vicente P Soloviev (Universidad Politécnica de Madrid)

Poster

Poster Session 1

Variational quantum algorithms (VQAs) (Cerezo et al. [2021]) are hybrid approaches between classical and quantum computation, where a classical optimizer proposes parameter configurations for a quantum parametric circuit which is iteratively measured. Each measured solution is assessed according to a cost function that evaluates the energy of the system, which is sought to be optimized. The...

96. A zk-SNARK Scheme for Quantum Computers

David Soler Garcia

Poster

The cryptographic primitive zk-SNARK allows users to prove knowledge of something without revealing its exact value. Using a secret value W ("witness") and a public value X, a zk-SNARK $\pi$ can be generated such that anyone who only knows $\pi$ and X can be sure that the prover must know W. As zero-knowledge proofs, zk-SNARKs meet the requirements of Completeness, Soundness and Zero...

90. Adiabatic quantum algorithm for the Bose-Hubbard model

María Cea (University of the Basque Country)

Poster

In recent years research has been carried out on algorithms to simulate quantum many-body systems in current NISQ devices. In particular, for the ground state finding problem, known to be QMA-complete, a quantum adiabatic algorithm can be used. On the other hand, the Bose-Hubbard model has gained impact lately because of the prediction of exotic phases of matter and because its experimental...

81. Amplified nanoscale detection of labeled molecules via surface electrons on diamond

Ainitze Biteri Uribarren (Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain), Pol Alsina Bolívar (Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain)

Poster

The development of new sensing techniques that reach nanoscale resolution would habilitate the detection of single molecules as well as their dynamics. In this regard, we present a detection protocol using a nitrogen vacancy center quantum sensor to measure the coupling between two electronic targets on a macromolecule via a dangling bond. The latter is an unpaired immobilized electron, which...

112. Analysis of Quantum Annealing Architectures: A Spin Glass Perspective

Gabriel Jaumá Gómez (CSIC Instituto de Física Fundamental)

Poster

Although quantum annealing has shown promising results, it still
struggles to outperform classical optimization algorithms. One of the
reasons for this is that the qubit connectivities in superconducting
circuits, which are one of the most promising platforms for quantum
annealing, are not complex enough. This work focuses on the analysis
of different architectures for quantum...

30. Benchmarking the Role of Particle Statistics in Quantum Reser- voir Computing

Mr Guillem Llodra (IFISC)

Poster

Poster Session 1

Quantum reservoir computing is a neuro-inspired machine learning approach harnessing the rich dynamics of quantum systems to solve temporal tasks. It has gathered attention for its suitability for NISQ devices, for easy and fast trainability, and for potential quantum advantage. Although several types of systems have been proposed as quantum reservoirs, differences arising from particle...

78. Casual query of multiloop Feynman integrals through Grover's algorithm

Andrés Rentería

Poster

In the context of high-energy physics, accurate theoretical predictions can be obtained by perturbation theory. However, higher-order contributions require the evaluation of complicated multi-loop Feynman integrals, which is a serious bottleneck in computational frameworks. In this work we present an application of a quantum algorithm to multi-loop Feynman integrals. We introduce a suitable...

77. Cat-state gadgets

Rafael Wagner (International Iberian Nanotechnology Laboratory)

Poster

One potential way to achieve significant progress in quantum computing is by using quantum devices to simulate quantum systems instead of relying on classical computers to perform the simulation. However, a challenge is to demonstrate that there is a fundamental difference between simulating physical systems using classical computers versus quantum computers. Formal complexity arguments often...

28. Cavity-assisted generation of steady-state entanglement between non-identical quantum emitters

Alejandro Vivas-Viaña (Departamento de Física Teórica de la Materia Condensada and Condesed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid)

Poster

Poster Session 1

Common wisdom suggests that, in order to entangle two quantum emitters, it is desirable that these have identical natural frequencies, since this facilitates cross talk between them and enables the type of collective dynamics that leads to entanglement [1]. However, the fabrication of quantum emitters with identical properties is a significant challenge in solid state physics.

In this work,...

98. Coherence for quantum-enhanced thermodynamic performance in steady-state quantum thermal machines

Jose Antonio Almanza Marrero (IFISC)

Poster

Quantum coherence has been shown to impact the operational capabilities of quantum systems performing thermodynamic tasks in a significant way, and yet the possibility of genuine coherence-enhanced thermodynamic operation remains unclear. Here we show that only the presence of energetic coherence ---coherence between levels with different energies--- in steady-state quantum thermal machines...

94. Contextuality with Pauli observables in cycle scenarios

RAMAN CHOUDHARY (International Iberian Nanotechnology Laboratory (INL), Braga, Portugal)

Poster

Contextuality is a fundamental, rigorous marker of non-classicality exhibited by quantum theory. Therefore, it seems natural to expect this non-classical feature to play a vital role as a resource for quantum computational advantage. Indeed, many such links have been unveiled recently, and many of these results boil down to contextuality relative to Pauli observables. For example, in [1] it...

106. Controlled fabrication of Nb-based dayem bridge Josephson Junctions for highly- replicable SQUIDs

Jorge Pérez Bailón (UNIZAR)

Poster

Superconducting quantum interference devices (SQUIDs) combine the physical phenomena of flux
quantization and Josephson tunneling, resulting in a device that is extremely sensitive to magnetic field
fluctuations. Due to their quantum behavior, SQUIDs are fundamental elements in the development of new
quantum technologies in the field of sensing and computing.
They have the ability to...

95. Correlation spectroscopy for nanoscale NMR with nitrogen-vacancy centers

Ana Martin (Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain)

Poster

Nanoscale NMR is a technique that enables the study of the structure and properties of materials at the nanoscale level. In this regime, NV centers can be utilized as highly sensitive magnetic sensors to detect the magnetic fields produced by nearby nuclei. By placing a target sample close enough to the NV ensemble (i.e. at tens of nanometers), standard thermal polarization is replaced by...

45. Decoding 13C hyperfine parameters in NV centers signals with deep learning

Estibaliz Garrote

Poster

Quantum sensors exploit quantum properties of matter to measure and detect with high accuracy, sensitivity and/or resolution. Among the different types of sensors available, sensors based on NV centers have the additional advantage that they can be used at room temperature. This characteristic opens the door to develop new measuring, inspection and diagnostic equipment for processes and...

110. Dispersive readout of molecular spin qubits

M Rubín Osanz (CSIC UNIZAR)

Poster

Magnetic molecules are attractive candidates to encode spin qubits [1,2]. We have performed the first
experiments to test the dispersive readout of qubits encoded in the spin states of a magnetic molecules by
means of a superconducting circuit [3]. We couple our molecules to lumped-element resonators (LERs)
fabricated at the Centro of Astrobiología (CAB) [4]. Sweeping the external magnetic...

42. Efficient quantum circuit simulation using tensor networks

alfred miquel pastor i momparler (Universitat de València)

Poster

Quantum circuit simulations on classical computers are essential to develop better quantum computers and algorithms. Evenmore when there are few noisy and small quantum computers available. Different approaches have been proposed to simulate quantum circuits such as full amplitude-vector evolution, Feynman paths, decisión diagrams or tensor networks.

We can simulate a quantum circuit by...

1. Emergence of Classicality in Stern-Gerlach Experiment via Self-Gravity

Sourav Kesharee Sahoo (Ph.D Scholar)

Poster Session 1

Emergence of classicality from quantum mechanics, a hotly debated topic, has had no satisfactory resolution so far. Various approaches including decoherence and gravitational interactions have been suggested. In the present work, the Schrödinger-Newton model is used to study the role of semi-classical self-gravity in the evolution of massive spin-1/2 particles in a Stern-Gerlach experiment....

107. Engineering remote spin-spin interactions by superconducting circuit design

Carolina del Río (INMA)

Poster

In spite of the staggering progress achieved in recent years [1], the computational volume of available
quantum processors still limits their application to problems of socio-economical interest. Hybrid platforms,
combining superconducting circuits and microscopic qubits, such as spins, provide additional opportunities
to achieve a higher degree of integration. In particular, schemes based...

16. Enhanced security bounds for quantum cryptography with arbitrary phase randomization

Xoel Sixto (UVigo)

Poster

Poster Session 1

Quantum key distribution (QKD) is a technique for sharing a secret key between two separated communicating parties, usually referred to as Alice and Bob. When employed in conjunction with the one-time-pad encryption scheme, QKD provides information-theoretically secure communications, regardless of the future progress of classical or quantum technologies. In recent years, the field of QKD has...

56. Enhancing scalability of quantum circuits through gate cutting

Guillermo Díaz Camacho (CESGA)

Poster

In the NISQ era, quantum algorithms are limited to circuits with reduced size. Hybrid classical-quantum algorithms, such as Variational Quantum Algorithms (VQAs), aim to solve the depth bottleneck problem by repeatedly running shallow parameterized circuits. However, the number of qubits in available QPUs and the memory in classical computers limit VQAs' applicability.
With the aim of...

84. Entanglement-assisted, noise-assisted, and monitoring-enhanced quantum bath tagging

Dr Donato Farina (ICFO-The Institute of Photonic Sciences)

Poster

The possibility of discriminating the statistics of a thermal bath using indirect measurements performed on quantum probes is presented. The scheme relies on the fact that, when weakly coupled with the environment of interest, the transient evolution of the probe toward its final thermal configuration is strongly affected by the fermionic or bosonic nature of the bath excitations. Using...

26. Experimental use of coherence and dimension in a programmable integrated interferometer

Anita Camillini (University of Minho, INL - International Iberian Nanotechnology Laboratory)

Poster

Poster Session 1

Quantum research is focused on using quantum systems to perform computations and tasks that are impossible with a classical approach. These quantum computational advantages are a result of exponential differences in the resources needed for classical and quantum systems to perform the same task. However, quantum information processing offers more than just computational power. There is a...

71. Exploring dispersive qubit readout in the strong driving limit.

Luciano Iván Pereira Valenzuela (Instituto de Física Fundamental)

Poster

Dispersive readout in superconducting circuits is a limiting factor in the performance of current quantum processors. Experimentally, it has been observed that increasing the intensity of the readout pulses improves the signal-to-noise ratio of the measurement up to some threshold, where non-dispersive effects and leakage to higher levels enter into play. In this work, we perform a numerical...

50. Exploring indefinite causal order effects in thermal devices powered by generalized measurements

Pedro Dieguez (International Centre for Theory of Quantum Technologies (ICTQT))

Poster

Poster Session 1

A quantum-controlled device may produce a scenario in which two general quantum operations can be performed in such a way that it is not possible to associate a definite order for their application. Such an indefinite causal order can be explored to produce nontrivial effects in quantum thermal devices. In this poster, we discuss a measurement-powered thermal device that consists of...

118. Exploring quantum spin models with Rydberg atom arrays

Daniel Barredo (Institut d'Optique-CNRS & CINN-CSIC)

Invited

Rydberg atoms in arrays of optical tweezers offer a new perspective for quantum simulation of many body problems. In this talk, I will give a brief overview about this platform and describe our efforts to control Rydberg interactions to explore different types of spin Hamiltonians. I will report on our recent implementations of the 2D Ising Hamiltonian [1] and the dipolar XY model [2] with...

88. Extracting Information from Partial Hamiltonian of Simple Molecules for Designing Efficient Variational Quantum Eigensolvers

Harshdeep Singh

Poster

This work aims to study the qubit Hamiltonian of a molecule term-by-term to understand their contributions, and if any information can be extracted by just considering a few selected terms of the Hamiltonian, a technique called partial Hamiltonian analysis (PHA). The transformation of a molecular Hamiltonian from the fermionic space to the qubit space[1] provides us with a series of qubit...

20. Finite-time Landauer principle at strong coupling

Alberto Rolandi

Poster

Poster Session 1

Landauer's principle gives a fundamental limit to the thermodynamic cost of erasing information. Its saturation requires a reversible isothermal process, and hence infinite time. We develop a finite-time version of Landauer's principle for a bit encoded in the occupation of a single fermionic mode, which can be strongly coupled to a reservoir. By solving the exact non-equilibrium dynamics, we...

46. Global optimization of MPS in quantum-inspired numerical analysis

Paula García-Molina (Institute of Fundamental Physics)

Poster

Poster Session 1

This work discusses the solution of partial differential equations using matrix-product states (MPS). The study focuses on the search for the lowest eigenstates of a Hamiltonian equation, for which five algorithms are introduced: imaginary time evolution, steepest gradient descent, an improved gradient descent, an implicitly restarted Arnoldi method and density-matrix renormalization group...

51. Guarantees on the quantum network structure of experimental implementations

Dr Andrés Ulibarrena (Heriot-Watt University)

Poster

Poster Session 1

One of the goals within the quantum information community is the development of robust and reliable quantum networks. On those networks we will be able to perform quantum communication protocols and quantum computations. As quantum network technology becomes commonplace, the need for certification tools will arise to answer questions regarding the properties of the network.
Our goal is to...

70. Hassle-free Extra Randomness from quantum state’s identicalness with untrusted components

Hamid Tebyanian (University of York)

Poster

This paper investigates a semi-device-independent protocol for quantum randomness generation constructed on the prepare-and-measure scenario based on the on-off-keying encoding scheme and with various detection methods, i.e., homodyne, heterodyne, and single photon detection schemes. The security estimation is based on lower bounding the guessing probability for a general case and is...

25. Improving quantum state transfer: Correcting non-Markovian and distortion effects

Guillermo F Peñas Fernández (Instituto de Física Fundamental CSIC)

Poster

Poster Session 1

Quantum state transfer is a key operation for quantum information processing. The original pitch-and-catch protocols rely on flying qubits or single photons with engineered wavepacket shapes to achieve a deterministic, fast and high-fidelity transfer. Yet, these protocols overlook two important factors, namely, the distortion of the wavepacket during the propagation and non-Markovian effects...

114. Inertial sensing using matter-wave interferometry

Dennis Schlippert (1Leibniz Universität Hannover, Institut für Quantenoptik)

Invited

In a Mach-Zehnder-type light pulse atom interferometer, matter waves are split, mirrored, and recombined using coherent atom optics. With the leading order phase shift scaling with the enclosed space-time area, the momentum transfer induced by the atom optics light pulses as well as the free evolution time are key to significantly enhanced sensitivity to inertial forces and motivate...

15. Light-matter entanglement in above-threshold ionization processes in atoms

Javier Rivera Dean (Instituto de Ciencias Fotónicas (ICFO))

Poster

Poster Session 1

Light-matter entanglement plays a fundamental role in many applications of quantum information science. Thus, finding processes where it can be observed is an important task. Here, we address this matter by theoretically investigating the entanglement between light, and electrons generated in above-threshold ionization (ATI) process, where an input strong-laser field rips out an electron from...

82. Low field NMR at the microscale with nitrogen vacancy centers

Pol Alsina Bolívar (Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080), Ainitze Biteri Uribarren (Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080)

quantum metrology and sensing

Poster

Nuclear Magnetic Resonance (NMR) experiments traditionally require high magnetic fields to achieve sufficient signal contrast. However, there is a growing interest to develop low-field NMR. On the one hand, because it is lower-cost and less-invasive than standard NMR; and on the other hand, due to its potential to resolve J couplings and Quadrupolar interactions with higher resolution. These...

57. Markovian dynamics of decoherence for two coupled oscillators in thermal environment

Somayeh Mehrabankar (Departamento de Física Teórica and IFIC, Universidad de Valencia-CSIC, 46100 Burjassot (Valencia), Spain)

Poster

Poster Session 1

Assuming an open quantum system consisting of two coupled oscillators, we investigate the evolution of quantum correlations and purity in an equilibrium thermal environment with regard to the Born-Markov approximation. We assume squeezed vacuum state as the initial state of the system and study the effect of repulsive and attraction interaction on the correlations. In addition, their...

93. Matchgate hierarchy: A Clifford-like hierarchy for matchgate circuits

Angelos Bampounis (International Iberian Nanotechnology Laboratory (INL) and Centre of Mathematics (CMAT), Universidade do Minho)

Poster

The teleportation model of quantum computation introduced by Gottesman and Chuang [1] motivated the development of the Clifford hierarchy, an increasing sequence of sets of quantum gates critical for fault-tolerant quantum computation based on Clifford circuits. We propose an analogous hierarchy in the context of matchgate circuits, another restricted class of quantum circuits that can be...

102. Multi-armed quantum bandits: applications to online learning of quantum states and quantum recommender systems

Josep Lumbreras (Centre for Quantum Technologies, National University of Singapore)

Poster

The multi-armed bandit problem is a simple model of decision-making with uncertainty that lies in the
class of classical reinforcement learning problems. Given a set of arms, a learner interacts sequentially
with these arms sampling a reward at each round and the objective of the learner is to identify the arm
with largest expected reward while maximizing the total cumulative reward. The...

10. Multi-dimensional Fourier series with high-dimensional quantum circuits

Berta Casas Font (Barcelona Supercomputing Center)

Poster

Poster Session 1

Quantum Machine Learning is the field that aims to integrate machine learning into quantum computation. In the past years, some works have shown that we can naturally generate one-dimensional Fourier series with a simple supervised quantum learning model. However, there is a lack of explanation of such models for generating Fourier series of larger data-dimension. In this work, we provide a...

97. Multiprotocol interoperable QKD integrated devices

Dr Daniel Balado Souto (Institute for Physical and Information Technologies (ITEFI), Spanish National Research Council (CSIC))

Poster

Quantum key distribution (QKD) is the fundamental method employed in quantum communications to guarantee total security in the transmission of information. This is achieved by the utilization of different proposed cryptographic protocols (like BB84, Ekert, MDI…) with different advantages and problems, as well as different strategies of codification (polarization, time-bin, phase, spatial…),...

83. No graph states can be prepared in quantum networks with bipartite sources

Owidiusz Makuta (Center for Theoretical Physics of the Polish Academy of Sciences)

Poster

In research concerning quantum networks, it is often assumed that the parties can classically communicate with each other. However, classical communication might introduce substantial delay to the network, especially if it is large. As the latency of a network is one of its most important characteristics, it is interesting to consider quantum networks in which parties cannot communicate...

21. On the applications of functional quantum abstract detecting systems

Dr Elías Combarro (University of Oviedo)

Poster

Poster Session 1

Quantum abstract detecting systems (QADS) provide a common framework to address detection problems in quantum computers [1]. A particular QADS family, that of combinatorial QADS [2], has been proved to be useful for decision problems on eigenvalues or phase estimation methods. In this work, we consider functional QADS, which not only have interesting theoretical properties (intrinsic detection...

17. PauliComposer: Compute Tensor Products of Pauli Matrices Efficiently

Sebastián V. Romero (Tecnalia Research & Innovation)

Poster

Poster Session 1

We introduce a simple algorithm that efficiently computes tensor products of Pauli matrices. This is done by tailoring the calculations to this specific case, which allows to avoid unnecessary calculations. The strength of this strategy is benchmarked against state-of-the-art techniques, showing a remarkable acceleration. As a side product, we provide an optimized method for one key calculus...

103. Probe thermometry with continuous measurements

mohammad mehboudi (University of Geneva, Genva, Switzerland)

Poster

Temperature estimation is crucial for characterizing samples in all natural sciences. A standard
approach is provided by probe thermometry, where a probe is brought into contact with the sample
and examined after a certain amount of time has passed. In many situations however, continuously
monitoring the probe may be preferred. Here we consider a minimal model, where the probe is...

31. Probing quantum entanglement from magnetic-sublevels populations: beyond spin squeezing inequalities

Guillem Müller-Rigat (ICFO)

Poster

Spin squeezing inequalities (SSI) represent a major tool to probe quantum entanglement among a collection of few-level atoms, and are based on collective spin measurements and their fluctuations. Yet, for atomic ensembles of spin-$j$ atoms and ultracold spinor gases, many experiments can image the populations in all Zeeman sublevels $s=-j, -j+1, \dots, j$, potentially revealing finer features...

43. Quantum associative memory with a single driven-dissipative non-linear oscillator

Adria Labay Mora (Institute for Cross Disciplinary Physics and Complex Systems (IFISC) UIB-CSIC)

Poster

Poster Session 1

Algorithms for associative memory typically rely on a network of many connected units. The prototypical example is the Hopfield model, whose generalizations to the quantum realm are mainly based on open quantum Ising models. We propose a realization of associative memory with a single driven-dissipative non-linear quantum oscillator exploiting its infinite degrees of freedom in phase space....

115. Quantum cavities based on magnonic textures

David García-Pons (Instituto de Nanociencia y Materiales de Aragón (CSIC-Universidad de Zaragoza), Zaragoza, España)

out of date

Poster

Solid state quantum computing and quantum sensing technologies are based on the strong coupling between qubits and a quantized field of excitations. Besides photons, the solid state offers a wide variety of bosonic excitations that can be emitted or absorbed such as, e.g., magnons, the quantum version of spin waves.
Magnonic cavities offer the advantage of operating at reduced wavelengths...

44. Quantum circuits measuring weak values and Kirkwood–Dirac quasiprobability distributions, with applications

Antonio Ruiz-Molero (University of Minho)

Poster

Poster Session 1

Weak values [1] and the Kirkwood-Dirac (KD) quasiprobability distribution [5, 3], recently connected with one another, have been associated with both foundational issues in quantum theory as well as advantages in quantum metrology. For example, the nonclassicality of weak values and KD distributions has been linked to quantum advantage in metrology [2] and quantification of quantum information...

68. Quantum Edge Detection

Santiago Llorens (Universitat Autònoma de Barcelona, Department of Physics)

Poster

We investigate the problem of quantum edge detection, which aims to identify the abrupt change between two domains composed of unknown quantum states. This task can be viewed as an extension of the quantum change point problem in more feasible scenarios.
We use the Schur-Weyl duality to compute the optimal success probability of detecting the edge in the asymptotic limit of a large number of...

53. Quantum Recurrent Neural Networks for Time Series Prediction

José Daniel Viqueira Cao (CESGA)

Poster

Time series are present in many sectors such as weather forecasting, economy, medicine, artificial intelligence, and industry. The analysis of these sets to predict unknown values of variables in a complex system requires sophisticated algorithms which require a high computational cost. Machine learning algorithms, like recurrent neural networks, lead to plausible solutions.
However, when...

100. Quantum theory in finite dimension cannot explain every general process with finite memory

Mr Josep Lumbreras (National University of Singapore)

Poster

Arguably, the largest class of stochastic processes generated by means of a finite memory consists of those that are sequences of observations produced by sequential measurements in a suitable generalized probabilistic theory (GPT). These are constructed from a finite-dimensional memory evolving under a set of possible linear maps, and with probabilities of outcomes determined by linear...

60. Quantum-inspired and Quantum metaheuristic algorithms: Insights and perspectives

JULIO ALBERTO LÓPEZ-GÓMEZ Not Supplied

Poster

Poster Session 1

Solving complex optimization problems remains, to this day, an area of intense research and a challenge for professionals in science, engineering, and industry. This context motivates the emergence of methods that efficiently deal with very diverse problems: multiobjective, with a large number of constraints, nonlinear or with uncertainty, among others. Bio-inspired and metaheuristic...

59. Real Quantum Amplitude Estimation and beyond

Alberto Pedro Manzano Herrero

Poster

Poster Session 1

In this talk I present the Real Quantum Amplitude Estimation algorithm, an extension of Quantum Amplitude Estimation which is sensitive to the sign of the amplitude. Moreover, I propose an extension of the methodology which recovers the complex amplitude.

63. Robustness and security of a noisy multiparty quantum summation protocol

Antón Rodríguez Otero (TNO, TU Delft master student)

Poster

Poster Session 1

Connecting quantum computers to a quantum network opens a wide array of new applications, such as securely performing computations on distributed data sets. Near-term quantum networks will however remain noisy and hence correctness and security of protocols is not guaranteed.

Therefore, we consider noisy protocols with imperfect shared entangled states. This paper takes a first step in...

37. Security of Decoy-State Quantum Key Distribution Against Trojan-Horse Attacks

Álvaro Navarrete Rodriguez (Universidad de Vigo)

Poster

Poster Session 1

Most security proofs of quantum key distribution (QKD) disregard the effect of information leakage from the users’ devices, and, thus, do not protect against Trojan-horse attacks (THAs). In a THA, the eavesdropper injects strong light into the QKD apparatuses, and then analyzes the back-reflected light to learn information about their internal setting choices. Only a few recent works consider...

128. Shorcuts for Adiabatic and Variational Algorithms in Quantum Chemistry

Inaki Iriarte-Zendoia (EHU Quantum Center, University of the Basque Country UPV/EHU)

Poster

Quantum computation has sparked a revolution in solving problems ranging from combinatorial
optimization or quantum chemistry to industrial applications. Numerous algorithm proposals have
emerged in recent years, including adiabatic and variational quantum algorithms, which have shown
promising results in current NISQ devices. To further reduce the quantum resources required,
digitalized...

66. Stochastic Optical Quantum Circuit Simulator (SOQCS) physical model and software structure.

Javier Osca

Poster

Poster Session 1

Linear optical elements in combination with post-selection can be used to perform general quantum computation [1]. SOQCS is a C++ library (with a Python port) [2] aimed to simulate optical circuits for light modeled as Fock wavepackets. The objectives of the library are to work as a design tool of optical circuits and to provide a mean to calculate the effect of different imperfections in...

109. Strong coupling for spin clock states in electronuclear spin qudits based on vanadyl porphyrin molecules

Ignacio Gimeno (INMA, UNIZAR)

Poster

The possibility of encoding several qubits in vanadyl porphyrin molecules hosting a S = 1/2 electronic spin
coupled to a I = 7/2 nuclear spin has been explored. A complete study of the spin Hamiltonian and the spin
dynamics has been performed via a combination of electron paramagnetic resonance, heat capacity,
magnetization and on-chip magnetic spectroscopy experiments performed on single...

74. The NEASQC Benchmark Suite

Diego Andrade Canosa Not Supplied (Universidade da Coruña)

Poster

The NEASQC (NExt ApplicationS of Quantum Computing) project investigates and develops Quantum-enabled applications that can take advantage of NISQ (Noise Intermediate-Scale Quantum) systems in fields such as drug discovery, CO2 capture, smart energy management, natural language processing, breast cancer detection, probabilistic risk assessment for energy infrastructures or inventory...

76. Thermodynamic effects of inefficient detection in continuously monitored systems

Mar Ferri Cortes (Universitat d'Alacant)

Poster

In open quantum systems, in order to establish the impact of quantum fluctuations during the evolution of a system, one needs to continuously monitor it while minimizing disturbance. The thermodynamics of systems which are subjected to continuous quantum measurement can be described using the formalism of quantum trajectories. However, in realistic scenarios, this measurement is not ideal:...

116. Title: Making the case for quantum machine learning

Vedran Dunjko (Universidad de Leiden)

Invited

Quantum machine learning (QML) is often put forward as one of the most likely quantum applications to bring about useful advantages, perhaps even in the near term.
Large-scale quantum computers, once available, will give definite answers to whether this is true, but to make the most out of the significant investments in experimental quantum computing, it is important to try to learn as much...

85. Towards a wearable magnetometer

Juan Luis Sánchez Toural (Universidad Autónoma de Madrid)

quantum metrology and sensing

Poster

We have demonstrated, using a single crystal of diamond, spin manipulation, polarization, and reading of electrons using a microwave antenna. The microwave field is used to manipulate the orientation of electron spins through electron spin resonance tuned by an external magnetic field. The electron spin is initialized optically using laser radiation and the photoluminescence spin reading of...

108. Waveguide QED in the Dipole Gauge

Sergi Terradas (UNIZAR)

Poster

Recent studies on the ultrastrong coupling of light and matter have pointed out the nuances of approximating
the number of energy levels of the matter system. In cavity QED systems it was shown that directly applying
the two-level approximation to a model describing the interaction with a momenta-like operator (as in the
Coulomb gauge) could lead to gauge dependent observables [1,2]....