Data-Gouv-ML/pcri-erc-participations-et-projets-laureats huggingface dataset:
Projet ERC : MEMO (Horizon 2020, appel 2019, Starting grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Fundamental constituents of matter
Entité participante : Durham University — Pays : Royaume-Uni — Rôle : Partner
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 0.0 €

Quantum field theory (QFT) is undoubtedly one of the most important achievements of modern theoretical physics, with broad applications ranging from condensed matter systems to elementary particle physics. Despite its successes, the current formulation of QFT is incomplete and we lack tools to address from first principles a wide variety of interesting physical systems, including the dynamics of quarks within protons, phase transitions, and high temperature superconductors. The present project aims at addressing this issue by establishing a novel, powerful and unconventional paradigm for QFT without relying upon the existence of a perturbative expansion. The cornerstone for such a paradigm is the following remark: in a wide variety of simple examples it is possible to compute exactly the values of several observables relying solely upon the knowledge of the spectrum of solitons of the given QFT. I call this effect the memory of solitons. My goal is to establish a research group that will develop and exploit the memory of solitons to study non-perturbative aspects of QFTs. The proposed strategy to approach this problem is twofold. On the one hand I focus on the simplest QFTs to develop my intuition on concrete and explicit examples: my laboratory consists of theories having supersymmetry and/or conformal symmetry where a plethora of exact results are available in the literature. On the other I exploit geometric engineering techniques in string theory, which gives access to the non-perturbative spectrum of QFTs from a completely different angle that allows exact computations to be performed, providing new insights into the mathematical structure of the theories involved. The combination of these techniques is so powerful that I have already obtained a wide variety of results that could not be derived by any other known method.

Mots-clés : non perturbative quantum field theory,solitons,string theory,geometric engineering,supersymmetry
Projet ERC : CurvedSusy (Horizon 2020, appel 2014, Starting grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Fundamental constituents of matter
Entité participante : University of Copenhagen — Pays : Danemark — Rôle : Partner
Acronyme de l'entité : UCPH
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 23012.75 €

Quantum field theory provides a theoretical framework to explain quantitatively natural phenomena as diverse as the fluctuations in the cosmic microwave background, superconductivity, and elementary particle interactions in colliders. Even if we use quantum field theories in different settings, their structure and dynamics are still largely mysterious. Weakly coupled systems can be studied perturbatively, however many natural phenomena are characterized by strong self-interactions (e.g. high T superconductors, nuclear forces) and their analysis requires going beyond perturbation theory. Supersymmetric field theories are very interesting in this respect because they can be studied exactly even at strong coupling and their dynamics displays phenomena like confinement or the breaking of chiral symmetries that occur in nature and are very difficult to study analytically. Recently it was realized that many interesting insights on the dynamics of supersymmetric field theories can be obtained by placing these theories in curved space preserving supersymmetry. These advances have opened new research avenues but also left many important questions unanswered. The aim of our research programme will be to clarify the dynamics of supersymmetric field theories in curved space and use this knowledge to establish new exact results for strongly coupled supersymmetric gauge theories. The novelty of our approach resides in the systematic use of the interplay between the physical properties of a supersymmetric theory and the geometrical properties of the space-time it lives in. The analytical results we will obtain, while derived for very symmetric theories, can be used as a guide in understanding the dynamics of many physical systems. Besides providing new tools to address the dynamics of quantum field theory at strong coupling this line of investigation could lead to new connections between Physics and Mathematics.

Mots-clés : quantum field theory,supersymmetry
Projet ERC : QUANTMATT (Horizon 2020, appel 2015, Starting grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Condensed matter physics
Entité participante : Max Planck Society — Pays : Allemagne — Rôle : Partner
Acronyme de l'entité : MPG
Type d'entité : Recherche
Financement ERC de l'entité : 90214.63 €

Quantum matter is condensed matter which properties are dominated by the quantum nature of its constituents. The two most fundamental properties of quantum mechanics are interference and entanglement. How do these properties, and their derivatives, show up in an experiment? And how does one control them? These are the fundamental questions addressed in this proposal. The study is divided into three main parts: many-body localization, topological insulator nanowires, and topological semimetals. Many-body localization is concerned with the interplay of interference and entanglement and is central to questions about quantum thermalization. I aim to understand experimental signatures of many-body localization as well as devising simulation schemes that allow us to conduct numerical experiments on many-body localization for larger system sizes than has been so far possible. The interplay of interference, topology and geometry is the central theme of the topic of topological insulator nanowires. I have in the past theoretically demonstrated the signatures of fundamental quantum phenomena in these systems, including perfectly transmitted mode and Majorana fermions. The major goal of this part of the project is to collaborate closely with experimental groups seeking to verify my past theories, by providing new and more detailed predictions for these systems. This requires to further understand experimental details, develop certain theoretical devices and simulation techniques based on them. The final part on topological semimetals is particularly timely in view of recent experimental realizations of Dirac semimetals and the impending realization of Weyl semimetals, which both can be roughly thought of as 3D analogs of graphene. I seek to understand their unique transport signatures and the interplay of disorder with 3D Dirac fermions. The three parts feed into and from each other both through unified concepts and common methodology.
Projet ERC : NEWMAT (Horizon 2020, appel 2020, Starting grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Fundamental constituents of matter
Entité participante : University of Stuttgart — Pays : Allemagne — Rôle : PI
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 1499915.0 €

Quantum mechanics becomes most fascinating when its counterintuitive phenomena are observable on a macroscopic scale. The goal of this project is to realize and study novel states of matter that are paradigmatic examples of such behaviour. My primary focus is the paradoxical supersolid state of matter, which combines the crystal structure of a solid with the frictionless flow of a superfluid. The very existence of this state has been debated intensively for over 60 years. After decades of inconclusive efforts in helium, I have recently observed evidence for this state in magnetic quantum gases. This discovery has raised a plethora of new questions, which can be addressed with neither magnetic atoms nor helium, and thus require fundamentally new experimental approaches. In this project I will use laser-cooled dipolar molecules to explore supersolidity far beyond the state of the art. Starting from an ultracold gas of molecules, I will study - from few to many-body - long-discussed scenarios for supersolidity. The use of flexible optical potentials will allow me to investigate the role of doping, defects, dimensionality and disorder on the formation and dynamics of a supersolid. By using high-resolution, single-molecule imaging, I will be able to follow the corresponding dynamics down to the most elementary level, where correlations and entanglement become accessible. A particular significant generalization of this scenario arises when the spatial ordering competes with magnetic ordering. The molecules employed exhibit both electric and magnetic dipole moments and thus naturally feature the additional degree of freedom required to realize spin models. This will enable studying further exotic states of matter in which topological effects are expected to emerge. The extraordinary clean and tunable experimental approach will facilitate a precise comparison with theory, and thus promises unprecedented insights into the nature of these new states of matter.

Mots-clés : supersolid,quantum many body physics,ultracold molecules,laser cooling
Projet ERC : Q-ECHOS (Horizon 2020, appel 2020, Consolidator grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Fundamental constituents of matter
Entité participante : Delft University of Technology — Pays : Pays-Bas — Rôle : PI
Acronyme de l'entité : TU Delft
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 2374300.0 €

Quantum physics has been at the very heart of understanding the inner workings of nature and has led to the beginning of a modern technological revolution. Over the past decades, more and more physical systems have been used in quantum experiments. Yet, despite their tantalizing theoretical potential, full and comprehensive quantum control over phonons, in particular of traveling acoustic waves, has remained an elusive goal, mainly due to technical challenges. I have recently been part of the exciting new developments that set the stage for the field of quantum acoustics. I now propose to investigate novel regimes and applications of quantum physics with quantum excitations of mechanical waves at the nanoscale. My aim is to be able to control acoustic phonons to the same level as we currently achieve in the manipulation of optical photons in quantum optics. I will use new concepts like on-chip phonon routing, filtering, delaying and single-phonon detection to achieve full quantum control over individual phonons. Q-ECHOS is based on novel ideas and approaches, which have only recently become experimentally accessible through state-of-the-art photonic crystal-based quantum optomechanical systems realized in my group. This will allow for the observation of new physical phenomena, understand the decoherence mechanisms of other quantum systems, create hybrid quantum devices and open up completely new possibilities for quantum information processing. The research will not only have lasting impact on optomechanics and quantum physics, but will also pave the way for new technologies, such as quantum transducers for sensor applications, as well as for novel classical communication technologies. The breakthroughs in quantum optomechanics and my strong track record in this area will allow me to achieve exciting results through Q-ECHOS that will break new grounds.

Mots-clés : quantum acoustics,quantum optomechanics,phonons
Projet ERC : NOQIA (Horizon 2020, appel 2018, Advanced grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Fundamental constituents of matter
Entité participante : Institute of Photonic Sciences — Pays : Espagne — Rôle : PI
Acronyme de l'entité : ICFO;ICFO-CERCA
Type d'entité : Recherche
Financement ERC de l'entité : 2164243.75 €

Quantum simulators (QS) are experimental systems that allow mimic hard to simulate models of condensed matter, high energy physics and beyond. QS have various platforms: from ultracold atoms and ions to superconducting qubits. They constitute the important pillar of quantum technologies (QT), and promise future applications in chemistry, material science and optimization problems. Over the last decade, QS were particularly successful in mimicking topological effects in physics (TEP) and in developing accurate quantum validation/certification (QVC) methods. NOQIA is a theory project, aimed at introducing the established field of QS+TEP+QVC into two novel areas: physics of ultrafast phenomena and attoscience (AS) on one side, and quantum machine learning (ML) and neural networks (NN) on the other. This will open up new horizons/opportunities for research both in AS and in ML/NN. For instance, in AS we will address the question if intense laser physics may serve as a tool to detect topological effects in solid state and strongly correlated systems. We will study response of matter to laser pulses carrying topological signatures, to determine if they can induce topological effects in targets. We will design/analyze QS using trapped atoms to understand and detect TEP in the AS. On the ML/NN side, we will apply classical ML to analyze, design and control QS for topological systems, in order to understand and optimize them. Conversely, we will transfer many-body techniques to ML in order to analyze and possibly improve performance of classical machine learning. We will design and analyze quantum neural network devices that will employ topology in order to achieve robust quantum memory or information processing. We will design/study attractor neural networks with topological stationary states, or feed-forward networks with topological Floquet and time-crystal states. Both in AS and ML/NN, NOQIA will rely on quantum validation and certification protocols and techniques.

Mots-clés : quantum simulators
Projet ERC : ECLIPSE (Horizon 2020, appel 2019, Starting grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Condensed matter physics
Entité participante : École Nationale Supérieure des Mines de Paris — Pays : France — Rôle : Partner
Acronyme de l'entité : Mines ParisTech PSL
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 288750.0 €

Quantum systems can occupy peculiar states, such as superposition or entangled states. These states are intrinsically fragile and eventually get wiped out by inevitable interactions with the environment. Protecting quantum states against decoherence is a formidable and fundamental problem in physics, which is pivotal for the future of quantum computing. The theory of quantum error correction provides a solution, but its current envisioned implementations require daunting resources: a single bit of information is protected by encoding it across tens of thousands of physical qubits. My proposal is to protect quantum information in an entirely new type of qubit with two key specificities. First, it will be encoded in a single superconducting circuit resonator whose infinite dimensional Hilbert space can replace large registers of physical qubits. Second, this qubit will be rf-powered, continuously exchanging photons with a reservoir. This approach challenges the intuition that a qubit must be isolated from its environment. Instead, the reservoir acts as a feedback loop which continuously and autonomously corrects against errors. This correction takes place at the level of the quantum hardware, and reduces the need for error syndrome measurements which are resource intensive. The circuits I will develop manipulate quantum states of light, whose utility transcends the long term goal of quantum computing, and can readily be used to probe fundamental properties of matter. In mesoscopic physics where a large number of particles exhibit collective quantum phenomena, the measurement tools to characterize subtle quantum effects are often lacking. Here, I propose to measure the spin entanglement of a single Cooper pair, by coupling a superconductor to a circuit composed of microwave resonators and a carbon nanotube. The spin entanglement can be swapped into microwave photons, which can be detected by deploying the arsenal of quantum limited microwave measurement devices.

Mots-clés : superconducting circuits,quantum error correction,quantum sensing,josephson junctions,carbon nanotubes
Projet ERC : ECLIPSE (Horizon 2020, appel 2019, Starting grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Condensed matter physics
Entité participante : École normale supérieure PSL — Pays : France — Rôle : Partner
Acronyme de l'entité : ENS PSL
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 31250.0 €

Quantum systems can occupy peculiar states, such as superposition or entangled states. These states are intrinsically fragile and eventually get wiped out by inevitable interactions with the environment. Protecting quantum states against decoherence is a formidable and fundamental problem in physics, which is pivotal for the future of quantum computing. The theory of quantum error correction provides a solution, but its current envisioned implementations require daunting resources: a single bit of information is protected by encoding it across tens of thousands of physical qubits. My proposal is to protect quantum information in an entirely new type of qubit with two key specificities. First, it will be encoded in a single superconducting circuit resonator whose infinite dimensional Hilbert space can replace large registers of physical qubits. Second, this qubit will be rf-powered, continuously exchanging photons with a reservoir. This approach challenges the intuition that a qubit must be isolated from its environment. Instead, the reservoir acts as a feedback loop which continuously and autonomously corrects against errors. This correction takes place at the level of the quantum hardware, and reduces the need for error syndrome measurements which are resource intensive. The circuits I will develop manipulate quantum states of light, whose utility transcends the long term goal of quantum computing, and can readily be used to probe fundamental properties of matter. In mesoscopic physics where a large number of particles exhibit collective quantum phenomena, the measurement tools to characterize subtle quantum effects are often lacking. Here, I propose to measure the spin entanglement of a single Cooper pair, by coupling a superconductor to a circuit composed of microwave resonators and a carbon nanotube. The spin entanglement can be swapped into microwave photons, which can be detected by deploying the arsenal of quantum limited microwave measurement devices.

Mots-clés : superconducting circuits,quantum error correction,quantum sensing,josephson junctions,carbon nanotubes
Projet ERC : Quantropy (Horizon 2020, appel 2020, Synergy grants)
Entité participante : Université Paris Cité — Pays : France — Rôle : Partner
Acronyme de l'entité : UP Cité
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 78478.75 €

Quantum systems that have been engineered to host correlated electronic states are of outstanding fundamental and technological interest. Often ‘exotic’ new quasi-particles emerge, such as Majorana fermions, whose inherent topological robustness forms the basis of a promising approach to quantum computation. Another recent example are sheets of pencil-lead graphene which superconduct with a proper twist between layers. Thermodynamic probes have been central for characterising new phases of matter in bulk materials. Low-dimensional systems offer greater opportunities for control, but probing their electronic states in a similar way is notoriously difficult, in part because of the small number of electrons involved. The objective of this project is to overcome this challenge and to develop a unique conceptual and experimental foundation for exploring correlated quantum states in low-dimensional systems by measuring thermodynamic quantities, in particular entropy. Entropy is one of the most fundamental of physical properties, and in recent years has been recognized as a key to understanding systems as diverse as qubits and black holes. Fully exploiting entropy measurements in mesoscopic physics will open up a new window to a mechanistic understanding of correlated quantum states in engineered structures, with promise for ground-breaking novel device paradigms. Members of the consortium have pioneered some of the few existing approaches to making thermodynamic measurements of low-dimensional systems. In combining our expertise, we will develop, test and explore a versatile suite of thermodynamic probes, and in particular i) demonstrate fractional entropy as an unequivocal observable for exotic states, including Majorana fermions; ii) develop thermodynamic measurement paradigms to probe correlated states in novel materials, in particular twisted bilayer graphene; and iii) achieve the first-time measurement of macroscopic entanglement entropy in solid-state systems.

Mots-clés : entropy,mesoscopic thermodynamics,thermodynamic probe,quantum engineering,correlated quantum systems
Projet ERC : Q-Feedback (Horizon 2020, appel 2019, Advanced grants)
Domaine scientifique : Physical Sciences and Engineering
Panel : Systems and communication engineering
Entité participante : École Nationale Supérieure des Mines de Paris — Pays : France — Rôle : Partner
Acronyme de l'entité : Mines ParisTech PSL
Type d'entité : Enseignement supérieur ou secondaire
Financement ERC de l'entité : 1005750.0 €

Quantum technologies, such as quantum computers and simulators, have the potential of revolutionizing our computational speed, communication security and measurement precision. The power of the quantum relies on two key but fragile resources: quantum coherence and entanglement. This promising field is facing a major open question: how to design machines which exploit quantum properties on a large scale, and efficiently protect them from external perturbations (decoherence), which tend to suppress the quantum advantage? Making a system robust and stable to the influence of external perturbations is one of the core problems in control engineering. The goal of this project is to address the above question from the angle of control systems. The fundamental and scientific ambition is to elaborate theoretical control methods to analyse and design feedback schemes for protecting and stabilizing quantum information. Q-Feedback develops mathematical methods to harness the inherently stochastic aspects of quantum measurements. Relying on the development of original mathematical perturbation techniques specific to open quantum systems, Q-Feedback proposes a new hierarchical strategy for quantum feedback modeling, design and analysis. The building block of a quantum machine is the quantum bit (qubit), a system which can adopt two quantum states. Despite major progress, qubits remain fragile and lose their quantum properties before a meaningful task can be accomplished. For this reason, a qubit must be both protected against external perturbations, and manipulated to perform a task. Today, no such qubit has been built. In collaboration with experimentalists, the practical ambition is to design, relying on the control tools developed here, qubits readily integrable in a quantum processing unit. The physical platform will be Josephson superconducting circuits. Q-Feedback is expected to demonstrate the crucial role of control engineering in emerging quantum technologies.

Mots-clés : quantum control,coherent feedback,decoherence control,control of open quantum systems