ERC FUNDED PROJECTS

Single-photon sources (SPSs) are systems capable of emitting photons one by one. These sources are of major importance for quantum-information science and applications. SPSs experiments generally rely on the optical excitation of two level systems of atomic-scale dimensions (single-molecules, vacancies in diamond…). Many fundamental questions related to the nature of these sources and the impact of their environment remain to be explored: Can SPSs be addressed with atomic-scale spatial accuracy? How do the nanometer-scale distance or the orientation between two (or more) SPSs affect their emission properties? Does coherence emerge from the proximity between the sources? Do these structures still behave as SPSs or do they lead to the emission of correlated photons? How can we then control the degree of entanglement between the sources? Can we remotely excite the emission of these sources by using molecular chains as charge-carrying wires? Can we couple SPSs embodied in one or two-dimensional arrays? How does mechanical stress or localised plasmons affect the properties of an electrically-driven SPS? Answering these questions requires probing, manipulating and exciting SPSs with an atomic-scale precision. This is beyond what is attainable with an all-optical method. Since they can be confined to atomic-scale pathways we propose to use electrons rather than photons to excite the SPSs. This unconventional approach provides a direct access to the atomic-scale physics of SPSs and is relevant for the implementation of these sources in hybrid devices combining electronic and photonic components. To this end, a scanning probe microscope will be developed that provides simultaneous spatial, chemical, spectral, and temporal resolutions. Single-molecules and defects in monolayer transition metal dichalcogenides are SPSs that will be studied in the project, and which are respectively of interest for fundamental and more applied issues.

1 996 848 €

Start date: 2018-06-01, End date: 2023-05-31

We propose to investigate a new frontier in Physics: the study of Magnetic systems using attosecond laser pulses. The main disciplines concerned are: Ultrafast laser sciences, Magnetism and Spin-Photonics, Relativistic Quantum Electrodynamics. Three issues of modern magnetism are addressed. 1. How fast can one modify and control the magnetization of a magnetic system ? 2. What is the role and essence of the coherent interaction between light and spins ? 3. How far spin-photonics can bring us to the real world of data acquisition and storage ? - We want first to provide solid ground experiments, unravelling the mechanisms involved in the demagnetization induced by laser pulses in a variety of magnetic materials (ferromagnetic nanostructures, aggregates and molecular magnets). We will explore the ultrafast magnetization dynamics of magnets using an attosecond laser source. - Second we want to explore how the photon field interacts with the spins. We will investigate the dynamical regime when the potential of the atoms is dressed by the Coulomb potential induced by the laser field. A strong support from the relativistic Quantum Electro-Dynamics is necessary towards that goal. - Third, even though our general approach is fundamental, we want to provide a benchmark of what is realistically possible in ultrafast spin-photonics, breaking the conventional thought that spin photonics is hard to implement at the application level. We will realize ultimate devices combining magneto-optical microscopy with the conventional magnetic recording. This new field will raise the interest of a number of competitive laboratories at the international level. Due to the overlapping disciplines the project also carries a large amount of educational impact both fundamental and applied.

2 492 561 €

Start date: 2010-05-01, End date: 2015-04-30

In the bioSPINspired project, I propose to use my experience and skills in spintronics, non-linear dynamics and neuromorphic nanodevices to realize bio-inspired spin torque computing architectures. I will develop a bottom-up approach to build spintronic data processing systems that perform low power ‘cognitive’ tasks on-chip and could ultimately complement our traditional microprocessors. I will start by showing that spin torque nanodevices, which are multi-functional and tunable nonlinear dynamical nano-components, are capable of emulating both neurons and synapses. Then I will assemble these spin-torque nano-synapses and nano-neurons into modules that implement brain-inspired algorithms in hardware. The brain displays many features typical of non-linear dynamical networks, such as synchronization or chaotic behaviour. These observations have inspired a whole class of models that harness the power of complex non-linear dynamical networks for computing. Following such schemes, I will interconnect the spin torque nanodevices by electrical and magnetic interactions so that they can couple to each other, synchronize and display complex dynamics. Then I will demonstrate that when perturbed by external inputs, these spin torque networks can perform recognition tasks by converging to an attractor state, or use the separation properties at the edge of chaos to classify data. In the process, I will revisit these brain-inspired abstract models to adapt them to the constraints of hardware implementations. Finally I will investigate how the spin torque modules can be efficiently connected together with CMOS buffers to perform higher level computing tasks. The table-top prototypes, hardware-adapted computing models and large-scale simulations developed in bioSPINspired will lay the foundations of spin torque bio-inspired computing and open the path to the fabrication of fully integrated, ultra-dense and efficient CMOS/spin-torque nanodevice chips.

1 907 767 €

Start date: 2016-09-01, End date: 2021-08-31

Topology provides mathematical tools to sort objects according to global properties regardless of local details, and manifests itself in various fields of physics. In solid-state physics, specific topological properties of the band structure, such as a band inversion, can for example robustly enforce the appearance of spin-polarized conducting states at the boundaries of the material, while its bulk remains insulating. The boundary states of these ‘topological insulators’ in fact provide a support system to encode information non-locally in ‘topological quantum bits’ robust to local perturbations. The emerging ‘topological quantum computation’ is as such an envisioned solution to decoherence problems in the realization of quantum computers. Despite immense theoretical and experimental efforts, the rise of these new materials has however been hampered by strong difficulties to observe robust and clear signatures of their predicted properties such as spin-polarization or perfect conductance. These challenges strongly motivate my proposal to study two-dimensional topological insulators, and in particular explore the unknown dynamics of their topological edge states in normal and superconducting regimes. First it is possible to capture information both on charge and spin dynamics, and more clearly highlight the basic properties of topological edge states. Second, the dynamics reveals the effects of Coulomb interactions, an unexplored aspect that may explain the fragility of topological edge states. Finally, it enables the manipulation and characterization of quantum states on short time scales, relevant to quantum information processing. This project relies on the powerful toolbox offered by radiofrequency and current-correlations techniques and promises to open a new field of dynamical explorations of topological materials.

1 499 940 €

Start date: 2018-02-01, End date: 2023-01-31

For nearly thirty years, the search for a room-temperature superconductor has focused on exotic materials known as cuprates, obtained by doping a parent Mott insulator, and which can carry currents without losing energy as heat at temperatures up to 164 Kelvin. Conventionally three main players were identified as being crucial i) the Mott insulating phase, ii) the anti-ferromagnetic order and iii) the superconducting (SC) phase. Recently a body of experimental probes suggested the presence of a fourth forgotten player, charge ordering-, as a direct competitor for superconductivity. In this project we propose that the relationship between charge ordering and superconductivity is more intimate than previously thought and is protected by an emerging SU(2) symmetry relating the two. The beauty of our theory resides in that it can be encapsulated in one simple and universal “gap equation”, which in contrast to strong coupling approaches used up to now, can easily be connected to experiments. In the first part of this work, we will refine the theoretical model in order to shape it for comparison with experiments and consistently test the SU(2) symmetry. In the second part of the work, we will search for the experimental signatures of our theory through a back and forth interaction with experimental groups. We expect our theory to generate new insights and experimental developments, and to lead to a major breakthrough if it correctly explains the origin of anomalous superconductivity in these materials.

1 318 145 €

Start date: 2016-08-01, End date: 2021-07-31

"Electronic spins are usually detected by their interaction with electromagnetic fields at microwave frequencies. Since this interaction is very weak, only large ensembles of spins can be detected. In circuit quantum electrodynamics (cQED) on the other hand, artificial superconducting atoms are made to interact strongly with microwave fields at the single photon level, and quantum-limited detection of few-photon microwave signals has been developed. The goal of this project is to apply the concepts and techniques of cQED to the detection and manipulation of electronic and nuclear spins, in order to reach a novel regime in which a single electronic spin strongly interacts with single microwave photons. This will lead to 1) A considerable enhancement of the sensitivity of spin detection by microwave methods. We plan to detect resonantly single electronic spins in a few milliseconds. This could enable A) to perform electron spin resonance spectroscopy on few-molecule samples B) to measure the magnetization of various nano-objects at millikelvin temperatures, using the spin as a magnetic sensor with nanoscale resolution. 2) Applications in quantum information science. Strong interaction with microwave fields at the quantum level will enable the generation of entangled states of distant individual electronic and nuclear spins, using superconducting qubits, resonators and microwave photons, as “quantum data buses” mediating the entanglement. Since spins can have coherence times in the seconds range, this could pave the way towards a scalable implementation of quantum information processing protocols. These ideas will be primarily implemented with NV centers in diamond, which are electronic spins with properties suitable for the project."

1 999 995 €

Start date: 2014-03-01, End date: 2019-02-28

Quantum computing is based on the manipulation of quantum bits (qubits) to enhance the efficiency of information processing. In solid-state systems, two approaches have been explored: • static qubits, coupled to quantum buses used for manipulation and information transmission, • flying qubits which are mobile qubits propagating in quantum circuits for further manipulation. Flying qubits research led to the recent emergence of the field of electron quantum optics, where electrons play the role of photons in quantum optic like experiments. This has recently led to the development of electronic quantum interferometry as well as single electron sources. As of yet, such experiments have only been successfully implemented in semi-conductor heterostructures cooled at extremely low temperatures. Realizing electron quantum optics experiments in graphene, an inexpensive material showing a high degree of quantum coherence even at moderately low temperatures, would be a strong evidence that quantum computing in graphene is within reach. One of the most elementary building blocks necessary to perform electron quantum optics experiments is the electron beam splitter, which is the electronic analog of a beam splitter for light. However, the usual scheme for electron beam splitters in semi-conductor heterostructures is not available in graphene because of its gapless band structure. I propose a breakthrough in this direction where pn junction plays the role of electron beam splitter. This will lead to the following achievements considered as important steps towards quantum computing: • electronic Mach Zehnder interferometry used to study the quantum coherence properties of graphene, • two electrons Aharonov Bohm interferometry used to generate entangled states as an elementary quantum gate, • the implementation of on-demand electronic sources in the GHz range for graphene flying qubits.

1 500 000 €

Start date: 2016-05-01, End date: 2021-04-30

"The physics of complex quantum systems with controllable interactions is emerging as a fundamental topic for a broad community, providing an opportunity to test theories of strongly correlated quantum many-body systems and opening interesting applications such as quantum simulators. Recently, in solid-state structures with effective photon-photon interactions the rich physics of quantum fluids of light has been explored, albeit not yet in the regime of strong photonic correlations. Exciting advances in cavity Quantum Electro-Dynamics (QED) and superconducting circuit QED make strong photon-photon interactions now accessible. A growing interest is focusing on lattices of coupled resonators, implementing Hubbard-like Hamiltonians for photons injected by pump driving fields. Similarly to electronic systems, the physics of large two-dimensional (2D) photonic lattices is a fundamental theoretical challenge in the regime of strong correlations. CORPHO has the ambition to develop novel scalable theoretical methods for 2D lattices of cavities, including spatially inhomogeneous driving and dissipation. The proposed methods are based on a hybrid strategy combining cluster mean-field theory and Wave Function Monte Carlo on a physical ‘Corner’ of the Hilbert space in order to calculate the steady-state density matrix and the properties of the non-equilibrium phases. We will study 2D lattices with complex unit cells and ‘fractional’ driving (only a fraction of the sites is pumped), a configuration that, according to recent preliminary studies, is expected to dramatically enhance and enrich quantum correlations. We will also investigate the interplay between driving and geometric frustration in 2D lattices with polarization-dependent interactions. Finally, the quantum control of strongly correlated photonic systems will be explored, including quantum feedback processes, cooling of thermal fluctuations and switching between multi-stable phases."

1 378 440 €

Start date: 2014-06-01, End date: 2019-05-31

Music performance is considered by many to be one of the most breath taking feats of human intelligence. That music performance is a creative act is no longer a disputed fact, but the very nature of this creative work remains illusive. Taking the view that the creative work of performance is the making and shaping of music structures, and that this creative thinking is a form of problem solving, COSMOS proposes an integrated programme of research to transform our understanding of the human experience of performed music, which is almost all music that we hear, and of the creativity of music performance, which addresses how music is made. The research themes are as follows: i) to find new ways to represent, explore, and talk about performance; ii) to harness volunteer thinking (citizen science) for music performance research by focussing on structures experienced and problem solving; iii) to create sandbox environments to experiment with making performed structures; iv) to create theoretical frameworks to discover the reasoning behind the structures perceived and made; and, v) to foster community engagement by training experts to provide feedback on structure solutions so as to increase public understanding of the creative work in music performance. Analysis of the perceived and designed structures will be based on a novel duality paradigm that turns conventional computational music structure analysis on its head to reverse engineer why a perceiver or a performer chooses a particular structure. Embedded in the approach is the use of computational thinking to optimise representations and theories to ensure accuracy, robustness, efficiency, and scalability. The PI is an established performer and a leading authority in music representation, music information research, and music perception and cognition. The project will have far reaching impact, reconfiguring expert and public views of music performance and time-varying music-like sequences such as cardiac arrhythmia.

2 495 776 €

Start date: 2019-06-01, End date: 2024-05-31

In France, the UK, Germany, the US, and Israel, a growing number of films and television series are set ‘behind the scenes’ of democratic regimes faced with terrorist threats. These works reveal a moral state of the world. They may be analysed as ‘mirrors’ of society, or as ideological tools. But they can also be understood as new resources for the education, creativity, and perfectibility of their audiences; as the emergence of a form of ‘soft power’ that can serve as a resource for public policies and democratic conversation. Because of their format (weekly/seasonal regularity, home viewing) and the participatory qualities of the Internet (tweeting, sharing, liking, chat forums), series allow for a new form of education by expressing complex issues through narrative and characters. As a result, TV series are increasingly recognised in current research. However, their aesthetic potential for visualising ethical issues and their capacity at enabling a democratic empowerment of viewers has not yet been analysed ; nor their power for confronting cultural and social upheavals underway, and developing a collective inquiry into democratic values and human security. DEMOSERIES brings together a team of scholars of moral philosophy, film studies, digital media and cultural data, sociology, law and political science, to explore a corpus of TV ‘security series’ from conception to reception. Doing so requires a particularist ethics based on attention to multi-faceted situations, paired with qualitative methods (interviews with security experts, showrunners, viewers; analyses of images, tropes, words; ethnography of reception) and quantitative methods (tweets and web analytics). By elucidating how these series are conceived by their creators and audiences, DEMOSERIES thus aims to understand if and how they might play a crucial role in building the awareness necessary for the safety of individuals and societies, and in creating shared and shareable values in the EU and beyond.

2 216 375 €

Start date: 2020-01-01, End date: 2024-12-31

Control of cell migration is crucial for many biological processes. Cells sense mechanical cues to guide their migration. As opposed to passive materials, living cells actively respond to the mechanical stimuli of their environment through the transduction of mechanical information into biochemical signaling events. These responses, particularly to rigidity, include differentiation, migration and alterations in cell-matrix and cell-cell adhesion and thus occur over a wide range of time and length scales. I propose to address the effect of substrate mechanical properties on cell migration using quantitative in vitro methods based on micro-fabrication and micro-mechanical techniques. My main objectives are to: 1/ Discover specific mechanisms that guide single cells toward stiffer substrates (a process known as durotaxis), investigate the range of stiffness-sensitive responses and determine the molecular mechanisms based on actin dynamics and cell adhesion assembly. 2/ Characterize the emergence of coordinated cell movements and thus how cells move in concert under external mechanical constraints. In addition to cell-substrate interactions, the role of cell-cell junctions is crucial in the transmission of mechanical signals over the cell population. By analyzing tissue dynamics at both mesoscopic and molecular scales, we hope to unravel how epithelial cell sheets mechanically integrate multiple adhesive cues to drive collective cell migration.3/ Elucidate the role of 3D mechanical environments in collective cell migration. In contrast to migration in 2D, cells in 3D must overcome the biophysical resistance of their surrounding milieu. Based on optical and innovative micro-fabrication techniques to modify the stiffness of 3D scaffolds, we will study its influence on cell migration modes and invasion. The goal of this interdisciplinary project is to understand how cells integrate mechanical adhesive signals to adapt their internal organization and ensure tissue integrity

1 762 734 €

Start date: 2014-06-01, End date: 2019-05-31

Quantum effects have been studied on photon propagation in the context of quantum optics since the second half of the last century. In particular, using single photon emitters, fundamental tests of quantum mechanics were explored by manipulating single to few photons in Hanbury-Brown and Twiss and Hong Ou Mandel experiments. In nanophysics, there is a growing interest to translate these concepts of quantum optics to electrons propagating in nanostructures. Single electron emitters have been realized such that single elementary electronic excitations can now be manipulated in the analog of pioneer quantum optics experiments. Electron quantum optics goes beyond the mere reproduction of optical setups using electron beams, as electrons, being interacting fermions, differ strongly from photons. Contrary to optics, understanding the propagation of an elementary excitation requires replacing the single body description by a many body one. The purpose of this proposal is to specifically explore the emergence of many body physics and its effects on electronic propagation using the setups and concepts of electron quantum optics. The motivations are numerous: firstly single particle emission initializes a simple and well controlled state. I will take this unique opportunity to test birth, life and death scenarii of Landau quasiparticles and observe the emergence of many-body physics. Secondly, I will address the generation of entangled few electrons quantum coherent states and study how they are affected by interactions. Finally, I will attempt to apply electron quantum optics concepts to a regime where the ground state itself is a strongly correlated state of matter. In such a situation, elementary excitations are no longer electrons but carry a fractional charge and obey fractional statistics. No manipulation of single quasiparticles has been reported yet and the determination of some quasiparticle characteristics, such as the fractional statistics remains elusive.

1 997 878 €

Start date: 2015-10-01, End date: 2020-09-30

The aim of the project FEMMES is to study the interplay between charge/spin tunneling and ferroelectricity in Ferroelectric Tunnel Junctions (FTJs) composed of two electrodes separated by a ferroelectric tunnel barrier. It will address fundamental issues such as the influence of interfaces and small thicknesses on the ferroelectricity, the dependence of the charge and spin tunneling on the ferroelectric orientation (electroresistance), the impact of the ferroelectricity of the barrier on the magnetism and spin polarisation of the electrodes. I propose to exploit FTJs and the intrinsic low-power of “ferroelectric writing”, to obtain: 1) a low-power electrical control of spin polarized electron sources for spintronics in FTJs with magnetic electrodes. 2) memristive FTJs mimicking the plasticity of synapses for an exploitation in neuromorphic analog circuits. This will be achieved by a synergetic approach combining: - ab initio calculations to determine the most appropriate combination of ferroelectric materials and electrodes and to obtain a complete description of the impact of the ferroelectric character on the transport properties. - the growth of selected heterostructures and extensive characterization of their structural, ferroelectric and magnetic properties. - the patterning of junctions (at the µm and nm scale) and the investigation of their transport and magnetotransport properties. - the evaluation and optimization of the potential of FTJs as electrically tunable spin sources for spintronics and memristors for neuromorphic circuits.

2 148 796 €

Start date: 2011-04-01, End date: 2016-03-31

Understanding the flows in planetary cores from their formation to their current dynamics is a tremendous interdisciplinary challenge. Beyond the challenge in fundamental fluid dynamics to understand these extraordinary flows involving turbulence, rotation and buoyancy at typical scales well beyond our day-to-day experience, a global knowledge of the involved processes is fundamental to a better understanding of the initial state of planets, of their thermal and orbital evolution, and of magnetic field generation, all key ingredients for habitability. The purpose of the present project is to go beyond the state-of-the-art in tackling three barriers at the current frontier of knowledge. It combines groundbreaking laboratory experiments, complementary pioneering numerical simulations, and fruitful collaborations with leaders in various fields of planetary sciences. Improving on the latest advances in the field, I will address the fluid dynamics of iron fragmentation during the later stages of planetary accretion, in order to produce innovative, dynamically reliable models of planet formation. Considering the latest published data for Earth, I will investigate the flows driven in a stratified layer at the top of a liquid core and their influence on the global convective dynamics and related dynamo. Finally, building upon the recent emergence of alternative models for core dynamics, I will quantitatively examine the non-linear saturation and turbulent state of the flows driven by libration, as well as the shape and intensity of the corresponding dynamo. In the context of an international competition, the originality of my work comes from its multi-method and interdisciplinary character, building upon my successful past researches. Beyond scientific advances, this high-risk/high-gain project will benefit to a larger community through the dissemination of experimental and numerical improvements, and allow promoting science through an original outreach program.

1 992 602 €

Start date: 2016-07-01, End date: 2021-06-30

How long does it take a random walker to reach a given target? This quantity, known as a first-passage time (FPT), has been the subject of a growing number of theoretical studies over the past decade. The importance of FPTs originates from the crucial role played by properties related to first encounters in various real situations, including transport in disordered media, diffusion limited reactions, or more generally target search processes. First-passage times in confinement, their optimization and their relationship to biophysical experiments are at the heart of this project. The following two issues will be investigated. 1) We will determine key first-passage observables of general scale-invariant random walks in confinement, which up to now have remained inaccessible: FPT distribution in the presence of several targets and/or several searchers, statistical properties of the explored territory, FPT distribution of a non-Markovian random walker. Beyond their theoretical interest, these developments will allow us to address in close connection with single-molecule experiments the importance of transport and spatial organization for gene transcription kinetics and stochastic gene expression. 2) We will address the question of the optimization of the search time. We have recently introduced a new type of search strategies, the intermittent strategies, which minimize the search time under general conditions. Here, the objectives are: (i) to determine new first-passage observables of these intermittent processes (eg the full FPT distribution) to allow the comparison of optimal strategies to experimental situations; (ii) to understand the physical mechanisms underlying real intermittent pathways and assess their optimality at the molecular (homologous recombination kinetics), cellular (search for infection markers by dendritic cells) and macroscopic scales (individual search behavior of ants); (iii) to use intermittent strategies to design efficient searches.

1 242 800 €

Start date: 2011-10-01, End date: 2017-09-30

Oxide compounds are usually highly ionic, with metal and oxygen ions carrying large positive and negative point charges. When inversion symmetry is broken as in ferroelectrics or at surfaces or interfaces, oxides can thus harbour large electric fields. This unleashes a quantum phenomenon known as the Rashba spin-orbit coupling that allows the generation of spin currents from charge currents and vice versa without ferromagnets, circumventing their drawbacks to perform these tasks. In the FRESCO project, we will combine the advantages of Rashba-driven spin-orbitronics phenomena with the ultralow switching energy of ferroelectrics. Building upon our demonstrations of giant spin-charge conversion at polar oxide interfaces and of non-volatile electoresistance in ferroelectric tunnel junctions, we will aim at a non-volatile electrical control of interconverted spin and charge currents in materials systems combining Rashba spin-orbit coupling with ferroelectricity. Guided by first-principles calculations, we will design and explore several families of atomically engineered polar heterostructures combining oxides and transition metal compounds. We will assess their spin-charge interconversion efficiency, its controllability by electric fields and its connection with the energy dependent spin Berry curvature. We will harness this controllability in spin-based non-volatile logic architectures operating through ferroelectricity-controlled spin-charge conversion. Building upon this, we will propose and explore several classes of devices including light-activated sources of spin currents based on photoferroelectricity, reconfigurable non-volatile logic gates, and tuneable THz sources and modulators. FRESCO will pioneer a new approach to generate spin currents and manipulate the static (or dynamic) magnetic states by electric fields beyond conventional magnetoelectricity, but retaining its advantageous low operating power, with a view towards attojoule electronics.

2 977 038 €

Start date: 2020-02-01, End date: 2025-01-31

Amorphous systems form a large fraction of the solid materials that surround us, from polymer glasses to mineral or metallic glasses, from toothpaste (a colloidal paste) to granular materials. Still, a theoretical framework for describing the mechanical properties of such materials, comparable to the dislocation theory that describes crystalline systems, is still missing. Our understanding of prominent experimental feature such as the heterogeneous character of deformation, or the temperature and rate dependence of the mechanical response, is very limited. These materials indeed combine several difficulties. In contrast to liquids or crystals, they are intrinsically out of equilibrium, and their microstructure presents a large statistical distribution of mechanically distinct local environments. The importance of the notion of heterogeneity in the mechanical behaviour of amorphous systems is being increasingly recognized, still there is no numerical or theoretical model that incorporates this microscopic feature into a macroscopic description of deformation and flow. The aim of the proposed research program is to build such models, within a multiscale approach seeking inspiration from dislocation dynamics, from the statistical physics of glasses and from the physics of dynamical critical phenomena. The proposed approach is based on a combination of intensive numerical simulations at the atomic scale and at a coarse grained scale, which will necessitate the development of efficient numerical schemes. The statistical analysis will allow us to understand the universal and non universal features of material behaviour in terms of the interactions between the atomic constituents, and to establish the validity and importance of new concepts such as mechanical activation or dynamical heterogeneities.

1 763 858 €

Start date: 2012-07-01, End date: 2017-06-30

Microcavity polaritons are half-light, half-matter composite bosons, which are formed in monolithic semiconductor microcavities of the proper design. Recently, Bose-Einstein condensation of polaritons has been reported, that constitutes a new class of quantum fluid out of equilibrium. Unlike cold atoms, superfluid Helium or superconductors, polaritons are in a driven-dissipative situation, and their mass amounts only to a negligible fraction of an electrons’. This unusual situation has already revealed very interesting phenomena. Moreover, every observables of the polariton fluid, including momentum, energy spectrum and coherence properties are directly accessed via optical spectroscopy experiments. In this project, we will fabricate and investigate new wide band-gap semiconductor nanostructures both capable of taking unprecedented control over the polariton environment, and capable of sustaining very hot and very dense quantum degenerate polariton fluids. Various confinement configurations - two, one and zero-dimensional -will be realized as well as advanced nanostructures based on traps and tunnel barriers. In these peculiar situations, the quantum degenerate polariton fluid will display a new and rich phenomenology. Hence, many premieres will be achieved like room temperature 1D quantum degeneracy, 1D quasi-condensate in solid-state systems, Josephson oscillations of polariton superfluids, and the fascinating Tonks-Girardeau state where strongly interacting bosons are expected to behave like fermions.

1 488 307 €

Start date: 2010-11-01, End date: 2015-10-31

Thermophoresis denotes the motion of dissolved species in fluids created by temperature gradients. In water, the origin of thermophoresis is multiple, complex and still a matter of active research activities for solutes such as proteins, DNA or colloids. Thermophoresis at small scales (sub-100 µm) aroused a strong interest this last decade because it makes the process faster and because of the development of important applications in life sciences, e.g. in bioanalytics. However, reducing the spatial scale makes quantitative and non-invasive measurements of temperature and molecular concentration more challenging. In the HiPhore project, using gold nanoparticles under illumination as nanosources of heat, I wish to achieve major breakthroughs in the field of microscale thermophoresis in liquids (MTL): (i) We will develop new microscopy tools and pioneer their use in the context of MTL: we will implement the possibility to shape arbitrarily complex microscale temperature profiles and to quantitatively image in parallel the resulting fields of temperature and molecular concentration using label-free advanced optical tools. (ii) Thanks to these tools, we will study the enigmatic origin of protein thermophoresis with a new glance. We will also explore a new regime, that I coin super-thermophoresis, consisting in thermophoresis in superheated liquid water up to 200°C. We have shown that such a metastable state can be achieved at ambient pressure using gold nanoparticles under illumination at their plasmonic resonance. (iii) Based on this gain of knowledge and know-how, we will develop two new applications of MTL. The first one consists in studying the thermal stability of proteins by thermophoresis with a label-free approach. The second one consists in using a superthermophoretic trap to enable for the first time the culture and the real-time observation of hyperthermophilic microorganisms (living up to 113°C) in vivo at ambient pressure under optical microscopy means.

1 922 973 €

Start date: 2018-03-01, End date: 2023-02-28

Boson gases confined in lattices present fundamental properties which strongly depart from their 3D counterparts. A notorious example is the honeycomb lattice, whose geometry results in massless Dirac-like states. By engineering the phase picked by the particles when tunneling from site to site, lattices also allow for the generation of artificial gauge fields. They result in very strong effective magnetic fields, opening the way to the observation of new quantum Hall regimes in neutral particles. In this context, polaritons appear as an excellent platform for the study of boson fluid effects in confined geometries. Polaritons are two-dimensional half-light/half-matter quasi-particles arising from the strong coupling between quantum well excitons and photons confined in a semiconductor microcavity. They are fully accessible by optical means and present strong non-linear properties. In this project, I will fabricate polariton microsstructures to study mesoscopic physics in 2D lattics. I will start by studying the non-linear Josephson dynamics in coupled micropillars, and engineer a double tunneling structure showing single polariton blockade. I will then fabricate a graphene-like honeycomb lattice, where I will study transport phenomena such as anomalous (Klein) tunneling and antilocalisation in the presence of disorder, phenomena originating from the Dirac-cone characteristic of honeycomb lattices. In the high density regime, I will investigate non-linear effects, and address the question of superfluidity of massless Dirac particles. Finally, I will undertake the realization of artificial gauge fields for polaritons. I will adapt to the polariton case a recent theoretical proposal to create artificial gauges in photons using coupled microdisks. Our results will have strong impact on current studies on the transport properties of graphene, of boson gases in atomic condensates, and also on the design of photonic systems with topological protection from disorder.

1 499 950 €

Start date: 2013-10-01, End date: 2018-09-30

Detecting and imaging magnetic fields with high sensitivity and nanoscale resolution is a topic of crucial importance for a wealth of research domains, from material science, to mesoscopic physics, and life sciences. This is obviously also a key requirement for fundamental studies in nanomagnetism and the design of innovative magnetic materials with tailored properties for applications in spintronics. Although a remarkable number of magnetic microscopy techniques have been developed over the last decades, imaging magnetism at the nanoscale remains a challenging task. It was recently realized that the experimental methods allowing for the detection of single spins in the solid-state, which were initially developed for quantum information science, open new avenues for high sensitivity magnetometry. In that spirit, it was recently proposed to use the electronic spin of a single nitrogen-vacancy (NV) defect in diamond as a nanoscale quantum sensor for scanning probe magnetometry. This approach promises significant advances in magnetic imaging since it provides quantitative and vectorial magnetic field measurements, with an unprecedented combination of spatial resolution and magnetic sensitivity, even under ambient conditions. The IMAGINE project intend to exploit the unique performances of scanning-NV magnetometry to achieve major breakthroughs in nanomagnetism. We will first explore the structure of domain walls and individual skyrmions in ultrathin magnetic wires, which both promise disruptive applications in spintronics. This will lead (i) to solve an important academic debate regarding the inner structure of domain walls and (ii) to the first detection of individual skyrmions in ultrathin magnetic wire under ambient conditions. This might result in a new paradigm for spin-based applications in nanoelectronics. We will then explore orbital magnetism in graphene, which has never been observed experimentally and is the purpose of surprising theoretical predictions.

1 498 810 €

Start date: 2015-09-01, End date: 2020-08-31

In the prospect of the circulation of concepts and practices and the permeability of artistic boundaries, this research program studies artistic vocabulary as it develops in the XVIIth century and transforms itself in the beginning of the XVIIIth century north of the Alps. Through words, the definition of concepts, the development of glossaries for artists and connoisseurs, and their subsequent insertion into intellectual networks may be grasped. Artistic vocabulary turns out to be a precious site of experimentation for these communities across Europe. Putting into relation artistic practices on one hand, and cultural transfers on the other, this lexicological study opens a new field, linked with the other knowledge domains. From two approaches, diachronic with the analyses of the dissemination of concepts, and synchronic with the study of their context, the purpose of this project is to provide a new research apparatus both reflexive and documentary: a critical dictionary of artistic terminology in French with multilingual entries, a database with the transcription of terms and definitions given by the art theorist themselves, and a volume of theoretical and methodological essays. Our aim is threefold. The first aim is to underline these artistic relations through the circulation of concepts and practices in Europe considered as the space of erudite communication. The second is to show the specificity of some terms and concepts in their own language, and the way they work in connection with the other languages and networks into which they fit, with the purpose of determining the moving boundaries of universality and identity within a culturally diversified geographic space. The third aim is to show that the early modern European artistic community is looking for a common language for the whole Republic of the Arts, which allows for the definition of the numerous artistic experiences which make the diversity of modern Europe.

1 679 796 €

Start date: 2013-04-01, End date: 2018-03-31

We propose to investigate the enzymes responsible for DNA replication and repair in micromanipulation experiments with a resolution of a single base. The detailed mechanism by which DNA is synthesized base after base and the coordination of the enzymes involved in this process are not fully understood. We shall develop new magnetic tweezers using lithographic techniques associated with evanescent field detection to address these issues. We shall build arrays of these devices working in parallel, each one on a single DNA molecule and where the measurement of its extension reveals enzymatic activity. The DNA molecule in these devices will form a hairpin the opening of which can be detected with a single base resolution. We will study the different enzymes involved in DNA replication. Firstly, we wish to follow in real time the incorporation of bases one by one by a DNA-polymerase and investigate the proof-reading mechanism of this enzyme. We shall also investigate the translocation mechanisms of different helicases involved in DNA replication and repair. Finally, we plan to study the cooperative action between different enzymes involved in the replication machinery with the help of parallelized micro-tweezers: the coupling between helicase and primase in the lagging strand synthesis, the coupling between the helicase and polymerase during leading strand synthesis and the coordination between leading and lagging strand synthesis. Moreover observing a DNA-polymerase at the single base level is the first step of a DNA sequencing method. Preliminary experiments demonstrate that the unzipping assay is a new way to determine the position of a small DNA sequence with single base resolution. We shall investigate different experimental schemes to achieve this goal.

2 193 566 €

Start date: 2011-09-01, End date: 2016-08-31

Leukocytes, white blood cells, patrol the vascular wall of our vessels in search of sites of inflammation. In the so-called leukocyte adhesion cascade, leukocytes flowing at high velocities (up to mm/s) impact the vessel wall, roll at µm/s, and finally migrate at nm/s to the site of inflammation. They are thus subjected to mechanical forces from sub-msec to several minutes. Complete understanding of the physical processes behind leukocyte adhesion requires an approach over multiple length and time scales, from single protein molecules to the whole cell. This is far from being established due, in part, to the lack of techniques covering the wide range of length and time scales involved. We have recently implemented high-speed atomic force microscopy (HS-AFM) to perform force spectroscopy measurements on biological samples with microsec time resolution. The novel acoustic force spectroscopy (AFS) traps hundreds of particles in parallel allowing hours-long measurements on single molecules. MechaDynA proposes to develop and apply these two novel nanotools to allow force measurements on living cells with the goal of obtaining a complete, multi-scale picture of the physics behind the leukocyte adhesion cascade over the widest dynamic range (µs-min). This will require development of HS-AFM technology and coupling with advanced optical microscopy. We will probe the binding strength of single adhesion complexes, and membrane and cytoskeleton mechanics at physiologically relevant time scales not explored so far. Technologically, it will establish HS-AFM and AFS as force measurement tools for living cells covering the widest temporal range. This will open the door to unexplored physical phenomena in cell biology, biological physics and soft condensed matter. Biomedically, the expected outcomes will provide a mechanistic description of the physical phenomena in leukocyte immune response that may lead to better diagnosis and therapeutics.

2 068 959 €

Start date: 2018-09-01, End date: 2023-08-31

Understanding electronic correlations remains one of the biggest challenges of theoretical condensed matter physics. Mesoscopic systems, where electronic confinement can be externally controlled, are natural test beds for understanding the effects of correlations, and the lack of proper techniques to take them into account is acute. This project aims at developing new tools for simulating correlated quantum mesoscopic devices. We will combine standard approaches for transport in mesoscopic quantum systems with new quantum Monte-Carlo algorithms designed to capture correlations in those devices. We will use modern programming paradigms to develop a versatile numerical platform designed to be easily used by other research groups. These numerical tools will be closely related to existing analytical approaches so that we shall be able to make contact with standard many-body theory while go beyond the limitations of the analytical approaches. We will apply this new set of techniques to several problems that have been puzzling the community for some time including quantum transport in low-density two-dimensional gases for both bulk disordered systems (“Two dimensional metal-insulator transition”) and quantum point contacts (“0.7 anomaly”). We will also apply our techniques to several new problems of increasing importance: at finite-frequency, electron-electron interactions play a central role and must be taken into account properly. We will discuss high frequency measurements such as quantum capacitances, ac conductance or photo-assisted transport in a variety of materials (twodimensional gases of electrons or holes, graphene, semi-conductor nanowires…) and leverage on our new numerical tools to go beyond the standard mean field description.

1 222 176 €

Start date: 2011-01-01, End date: 2015-12-31

"Biological motion and forces originate from mechanically active proteins operating at the nanometer scale. These individual active elements interact through the surrounding cellular medium, collectively generating structures spanning tens of micrometers whose mechanical properties are perfectly tuned to their fundamentally out-of-equilibrium biological function. While both individual proteins and the resulting cellular behaviors are well characterized, understanding the relationship between these two scales remains a major challenge in both physics and cell biology. We will bridge this gap through multiscale models of the emergence of active material properties in the experimentally well-characterized actin cytoskeleton. We will thus investigate unexplored, strongly interacting nonequilibrium regimes. We will develop a complete framework for cytoskeletal activity by separately studying all three fundamental processes driving it out of equilibrium: actin filament assembly and disassembly, force exertion by branched actin networks, and the action of molecular motors. We will then recombine these approaches into a unified understanding of complex cell motility processes. To tackle the cytoskeleton's disordered geometry and many-body interactions, we will design new nonequilibrium self consistent methods in statistical mechanics and elasticity theory. Our findings will be validated through simulations and close experimental collaborations. Our work will break new ground in both biology and physics. In the context of biology, it will establish a new framework to understand how the cell controls its achitecture and mechanics through biochemical regulation. On the physics side, it will set up new paradigms for the emergence of original out-of-equilibrium collective behaviors in an experimentally well-characterized system, addressing the foundations of existing macroscopic "active matter" approaches."

1 491 868 €

Start date: 2016-06-01, End date: 2021-05-31

Transition metal oxides possess a broad range of functionalities (superconductivity, magnetism, ferroelectricity, multiferroicity) stemming from the interplay between structural effects and electronic correlations. Recent work has revealed exciting physics at their interfaces, including two-dimensional (2D) conductivity and superconductivity in the electron gas that forms at the interface between two band insulators, LaAlO3 and SrTiO3. However, to date, no interfacial system has truly shown electronic properties that are absent from the phase diagram of both bulk constituents. I argue that to fully embrace the immense potential of oxide interfaces and unveil unprecedented electronic phases, combining insulators with stronger electronic correlations is mandatory. At the crossroad between strongly-correlated electron physics, microelectronics and spintronics, the MINT project will pioneer routes toward a new realm of solid-state physics. MINT will harness electronic and magnetic instabilities in correlated oxides to craft new electronic phases controllable by external stimuli. These phases will be generated by the synergic action of strain engineering, interfacial charge/orbital/spin reconstruction and octahedra connectivity control, using rare-earth titanate RTiO3 Mott-Hubbard insulators as templates. Emerging states that are foreseen include 2D electron gases with ferroic order, superconductivity at relatively high temperature, topological states and new forms of multiferroicity and magnetoelectric coupling. The discovery of any of these new states would represent a major breakthrough in oxide electronics. They will open possibilities for innovative devices yielding giant electroresistance without ferroelectrics, and new schemes to control spin currents by electric fields. At full term, MINT will establish whether oxide interfaces will live up to their expectations and start in the coming decades a technological revolution comparable to that of silicon.

1 998 026 €

Start date: 2014-10-01, End date: 2019-09-30

"The project will explore many-body physics in emergent quantum Hall effect systems (graphitic layers and surface states of topological insulators) and in layered metals of transition metal dichalcogenides using magneto-optical spectroscopy - unconventional for this purpose, but uniquely applicable to these unconventional systems. Studying the inter Landau level excitations (with Raman scattering techniques) in graphene and its bilayer we will test the basic principles of the role of electron-electron interactions in the regime of the quantum Hall effect. Employing high sensitivity microwave absorption methods, we will attempt to solve one of the most controversial issues in the physics of graphene: the nature of the low temperature ground state of the graphene bilayer. The magneto-optical response (in the far-infrared range) of three dimensional topological insulators will be investigated with the aim of demonstrating a new (half odd-integer) quantum Hall effect of their surface states and possible new exotic ground states of single-cone Dirac fermions. Finally, with a fresh experimental approach (cyclotron resonance absorption on NbSe2 and TaS2 and their thin layers) we will shed new light on one of the most intriguing phenomena in strongly correlated systems: competition between an insulating behaviour (charge density wave state in our case) and the ideal-conductor, superconductivity phase."

1 934 041 €

Start date: 2013-03-01, End date: 2018-02-28

In low-dimensional systems the strength of electronic interactions is enhanced, which can give rise to fascinating phenomena such as charge fractionalization, spin-charge separation and fractional or non-Abelian statistics. Furthermore, the effects of disorder and external factors (such as the substrate, the leads, magnetic fields, or the coupling with a gate or an STM tip), are much stronger in low-dimensional systems than in three-dimensional systems, and can greatly alter their properties. The first goal of this project is to find experimental signatures of the exotic phenomena caused by interactions, both in carbon nanotubes, and in regular and graphene fractional quantum Hall systems. The second goal is to understand how the interplay between disorder, interactions and external factors impacts the physics and the possible technological use of nanotubes and graphene in electronic nanodevices. To achieve these goals I intend to calculate theoretically quantities measurable by electronic transport, such as the conductance and the noise, in particular the noise at high-frequencies, as well as quantities measurable by scanning tunneling microscopy (STM), such as the local density of states (LDOS). Furthermore I intend to analyze and explain the recently developed STM experiments on graphene, and to propose new STM measurements that will elucidate the physics of graphene in the fractional quantum Hall regime. Some of the theoretical techniques that I plan to use are the perturbative non-equilibrium Keldysh formalism, conformal field theory and the Bethe ansatz, the T-matrix approximation, the Born approximation and numerical methods such as ab-initio and recursive Green's functions.

1 041 240 €

Start date: 2011-05-01, End date: 2016-04-30

Phonons (quanta of vibration) play a major role in many of the physical properties of condensed matter. One of the most striking features of acoustic phonons is their ability to interact with virtually any other excitation in solids. Recent progress in the design, fabrication and control of nanomechanical systems has paved the way to explore new frontiers in the classical and quantum worlds. Devices based on semiconductor quantum dots (QDs) have been recently demonstrated to perform as near-ideal single photon sources, a very promising platform for developing a solid-state quantum network. The phonon engineering, however, remains an unexplored knob in the quantum information toolbox. The goal of this project is to explore new horizons in nanophononics by developing novel phononic networks with full control on the phonon dynamics, and unprecedented structures capable of acoustically interact with single QDs, bridging the gap between nanophononics and semiconductor QD quantum optics. AlGaAs based semiconductor cavities are capable of confining simultaneously photons and phonons. The building blocks of the proposed research are semiconductor pillar microcavities and single QDs deterministically positioned to maximize their interaction with the confined electromagnetic and elastic fields. To achieve our main goal we set three major objectives: 1) To develop novel one- and three-dimensional optophononic resonators and develop appropriate phononic measuring techniques; 2) To engineer nanophononic networks working in the tens-of-GHz range; and 3) To demonstrate first phonon cavity quantum electrodynamics phenomena for a single artificial atom coupled to a phononic cavity. Shaping the phononic environment opens exciting perspectives for solid state quantum applications, by providing a full control over the main source of decoherence and actually using it as a powerful resource to eventually transfer the quantum information.

1 499 375 €

Start date: 2017-02-01, End date: 2022-01-31

We plan to develop and make use of novel out-of-equilibrium spectroscopy techniques that give access to energy transfers in electronic nanocircuits. The unveiled information will be used to investigate promising quantum phenomena and to explore new routes to control the mechanisms that limit their potentialities for nanoelectronics. The proposals backbone is the spectroscopy of the fundamental electronic states energy distribution function f(E) that we demonstrated this fall 2009: by using a quantum dot as an energy filter, we performed the first measurement of a non-equilibrium f(E) in a semiconductor nanocircuit. We plan not only to employ it, but also to develop complementary techniques which will further widen our range of investigation. We anticipate this f(E) toolbox will be crucial for the rising field of out-of-equilibrium mesoscopic physics. We will first examine through the unexplored facet of heat transport the quantum Hall effect regimes, which exhibit a large variety of puzzling many-body quantum phenomena and are of particular interest for their metrology applications and quantum information potentialities. The planed experiments will be done for various out-of-equilibrium situations, which will permit us to address longstanding open questions, such as the nature of pertinent excitations, and to test original ways to increase quantum effects. We will also perform direct energy exchange measurements to investigate the inelastic mechanisms that set the length and energy scales of coherent and out-of-equilibrium physics in nanocircuits. The novel f(E) spectroscopy will permit us to take advantage of the two-dimensional electron gas circuits high modularity to study many transport regimes and geometries that remain unexplored from this revealing viewpoint.

1 454 400 €

Start date: 2010-12-01, End date: 2015-11-30

The objective of this project is to explore novel phenomena of heavy fermion systems. The focus will be on low temperature novel properties such as quantum criticality, unconventional superconductivity and multipole ordering, which will leads to new horizon not only of heavy fermion physics, but also of material science. We will concentrate on: (1) new materials and high quality single crystals, (2) precise temperature-pressure-field (T,P,H) phase diagrams, (3) quantum singularities and Fermiology, (4) the mechanism of unconventional superconductivity including ferromagnetic superconductor, (5) field-induced phenomena. To reach our targets, we will first attempt to grow many new compounds based on U, Ce, Yb and other rare earth elements with a careful choice of target, using various techniques. Very high quality single crystals can be a breakthrough in this field of research, in particular for unconventional superconductivity. Then, we will measure their low temperature properties with various experimental techniques under extreme conditions, namely low temperature, high field, high pressure. Activities of material growth and studies of their properties will be coordinated in order to provide rapid a feedback. This work will be comforted by theoretical work. To carry out specific experiments, we will develop a new AC calorimetry system under extreme conditions and a de Haas-van Alphen (dHvA) measurement system. With this experimental method, we aim to directly observe the heavy electronic state. This is a major issue to clarify the possible Fermi surface instability at quantum singularities. The high quality samples will be supplied to other groups in order to extend our macroscopic and microscopic experimental multi approach.

1 500 000 €

Start date: 2010-11-01, End date: 2015-10-31

The fluctuation-dissipation theorem is a prominent milestone in Physics: It links the dissipative response of a physical system to its fluctuations, and provides a microscopic understanding of macroscopic irreversibility. Recent theoretical advances that have generalized the original fluctuation-dissipation theorem to non-linear quantum systems even far from equilibrium, ask for an experimental test, which is the aim of the project. We will measure the current fluctuations and dissipative response of driven quantum systems whose non-linearity arises from strong interactions. We will exploit the flexibility offered by nano-patterned high purity 2D electron gases in order to realize single electron channels in different regimes: 1/ interacting strongly with a single electromagnetic mode (Dynamical Coulomb Blockade of a quantum point contact), 2/ interacting with a single magnetic impurity (Kondo effect in quantum dots), 3/ driving the 2D gas in the fractional quantum Hall effect where current is carried by strongly correlated 1D channels prototypical of Luttinger liquids. Last, we will address a fundamental issue raised in the early days of quantum mechanics: how long does it take for a particle to cross a classically forbidden barrier? While Wigner-Smith’s theorem links the issue to the density fluctuations within the barrier, the fluctuation-dissipation theorem links it further to a quantum relaxation resistance. A full investigation of fluctuation-dissipation relations including quantum effects requires measurements at frequencies hf>k_BT. With the available dilution refrigeration techniques it implies measuring in the few GHz range. Since quantum conductors have an impedance h/e^2~25.8 kohm much larger than the 50ohm impedance of microwave components, new microwave methods able to deal with large impedance values will be developed. They will be based on the extension to finite magnetic field of the wide-band impedance matching methods recently developed by the PI.

1 500 000 €

Start date: 2015-05-01, End date: 2020-04-30

We shall study non-equilibrium many-body quantum systems, considering local interactions in one or two spatial dimensions in situations where the generator of time evolution in the bulk of the system is unitary whereas the incoherent processes are limited to the system's boundaries. We foresee a mathematical theory of dynamical quantum phases of matter with applications in the theory of quantum transport and nanoscale devices that manipulate heat, information, charge or magnetization. Our steady-state setup represents a fundamental paradigm of mathematical statistical physics which has been pioneered by the PI, who gave the first explicit solution for boundary driven/dissipative strongly interacting many-body problem (XXZ spin 1/2 chain) which answered a long debated question on strict positivity of the spin Drude weight at high temperature. The main focus of OMNES will be centered on exploring the following three interconnected pathways: Most importantly, we shall develop a general framework for exact solutions of non-equilibrium integrable quantum many-body models, in particular the steady states and relaxation modes, and develop quantum integrability methods for non-equilibrium many-body density operators. Fundamentally new concepts which are expected to emerge from these studies, relevant beyond the context of boundary-driven/dissipative systems, are novel quasilocal conservation laws of the bulk Hamiltonian dynamics. Second, we shall investigate relevance of exact solutions in physics of generic systems which are small perturbations of integrable models and explore the problem of stability of local and quasilocal conserved quantities under generic integrability-breaking perturbations. Third, we shall formulate and study the problem of quantum chaos in clean lattice systems, in particular to establish a link between random matrix theory of level statistics and kinematic and dynamical features of lattice models with sufficiently strong integrability breaking.

2 041 000 €

Start date: 2016-10-01, End date: 2021-09-30

This project aims at studying experimentally the out of equilibrium fluctuations in strongly confined fluids. Three main problems will be analyzed : a) The effects on the dynamics when the fluctuations are confined in a volume smaller than the spatial correlation length; b) The fluctuations of the injected and dissipated power in out of equilibrium in highly confined systems, where extreme events may produce an instantaneous ''negative entropy production rate''. c) Are fluctuations a limiting factor for application ? Might they be useful ? Our strategy is to enhance the role of fluctuations and correlations working close to the critical point of a second order phase transition. We will work at the critical point of mixing of either a binary mixture of fluids or of polymer blends, whose microscopic time scales and correlation lengths are much longer than those of binary mixtures of simple fluids. The local measurements and the confinement will be realized using an original ultra low noise Atomic Force Microscopy (AFM) developed in our laboratory. This AFM will be used in association with a near field aperture free light scattering technique, local and global dielectric techniques and evanescent waves imaging. This experimental set up, measuring local and global variables, will give new insight to two other interesting phenomena that are present in the critical regions : the finite size effects (such as dimensional crossover and time dependent critical Casimir effect) and the relaxation towards equilibrium after a quench at the critical point. These two phenomena have been widely investigated both theoretically and numerically butonly a few experiments have tried to measure directly the local fluctuations of confined fluids. Due to the universal nature of phase transitions the results can be applied to many other systems in which measurements are more complicated.

2 376 117 €

Start date: 2011-03-01, End date: 2016-12-31

Philosophy in Context : Arabic and Syriac manuscript transmissions in the Mediterranean (PhiC) This project aims to solve two major difficulties in research in the history of philosophy: 1) understanding the conditions of the reception and the transmission in the Mediterranean World of philosophy of Greek tradition in the Arabic and Syriac languages; 2) discovering the numerous works buried in libraries in a systematic way, instead of by chance. Thanks to a methodical pooling of the information given in the catalogs of manuscripts and, much more, to the systematic examination of the collections, we will be able not only to identify new texts but also get all kinds of information about the places and the institutions where the texts circulated, their copyists, sponsors, readers, etc. It will thus be finally possible to get a clear idea of how the products of pure reason were welcomed in Islam, and of the motivations of the collectors of manuscripts in Europe since the Renaissance (was it to satisfy the needs of scholarship, to translate the texts or to provide direct inspiration for creative thinking?). This work will be based on the cross-information allowed by the ABJAD database, that will be operational within the project itself. This project thus requires a strongly interdisciplinary approach, combining a thourough knowledge in the history of philosophy, philology, codicology and computer science.

2 495 316 €

Start date: 2011-03-01, End date: 2016-02-29

"This project concerns the field of coherent, nonlinear, ultrafast light-matter interaction on a quantum level in solids. It proposes to experimentally explore limits of: i) internal coherence of an individual emitter; ii) radiative coupling between pairs of emitters. A potential long term application of this work could be envisaged, as one can expect that individual emitters could serve as qubits for implementations of optically controlled quantum information processing in solids. As individual emitters we will employ excitons in semiconductors: either bound to impurities or confined in quantum dots. Firstly, by embedding the latter into upright photonic nanowires, that are now available in the team, we will amplify the collection of their coherent optical response by nearly four orders of magnitude as compared to the current state-of-art. This will provide an unprecedented access to their coherent as well as dephasing interaction with phonons. It will also enable retrieval of their n-wave mixing responses to scrutinize coherent couplings within an individual emitter. The second objective is the demonstration of an efficient, controllable and non-local coherent coupling mechanism between distant emitters, which is a prerequisite for the construction of quantum logic gates and networks. Here, such a radiative coupling will be demonstrated and manipulated using resonant emitters embedded into in-plane one-dimensional waveguides, which permit virtually unattenuated propagation of coherence. The internal and propagative coherence of individuals and radiatively coupled pairs will be explored using beyond-the-state-of-the-art methods of coherent nonlinear spectroscopy. Specifically, we will develop a spatially-resolved heterodyne spectral interferometry combined with ultrafast pulse-shaping. The proposed advanced methodology of this ERC project can be associated with techniques developed in other domains, like nuclear magnetic resonance and astrophysics instrumentation."

1 499 708 €

Start date: 2012-12-01, End date: 2017-11-30

Surfaces play a crucial role in the interaction of a material with its environment. Recent advances in Soft Matter physics reveal the extraordinary properties of surfaces with complex physico-chemical modifications. Of particular interest is the influence of such modifications on the wetting and flow of simple or complex fluids. Despite growing research efforts, a sound understanding and large-scale applications remain out of reach due to the difficulty of creating complex surfaces with satisfying control and cost. In particular, no technique exists to reliably modify surfaces within complex materials, like micro-porous solids. I therefore propose to develop an original bottom-up approach which relies on the self-organisation of interfacially active agents (polymers, particles) at the interface between two fluids. Using microfluidic techniques and the self-ordering of equal-volume drops under gravity, I will create highly periodic emulsions from these fluids which are stabilised by one type of agent. Solidification of the continuous phase (including the agent) and removal of the discrete phase will lead to the creation of a micro-porous solid with well-defined morphology to which the agent confers the desired surface modification (polymer brush, surface roughness). In systematically comparing the properties of these porous solids with those of flat modified surfaces, I aim to solidly correlate their surface properties with the resulting wetting/flow properties of simple and complex fluids. Building on this understanding and the acquired technical knowhow I aim to realise two long-sought applications: a supersponge & a liquid spring. To establish my research group as a world leader in this rapidly evolving and competitive domain at the interface between physics and chemistry, I need to tackle this project at different length scales and levels of complexity with a long term vision. At my career stage only an ERC Starting Grant can provide me with this possibility

1 499 973 €

Start date: 2012-12-01, End date: 2017-11-30

"A quantum dot (QD) in a microcavity is an ideal single spin-single photon interface: the spin of a carrier trapped inside a QD can be used as a quantum bit and the coupling to photons can allow remote spin entanglement. A QD in a cavity can also generate single photons or entangled photon pairs, often referred to as flying quantum bit. Controlling the QD spontaneous emission is crucial to ensure optimal coupling of the photon and spin states. The present project relies on a unique and original technology we have developed which allows us to deterministically control the QD-cavity system. With this technique, we can fabricate a large number of identical coupled QD-cavity devices operating either in the weak or strong coupling regime. The potential of the technique has been proven by the fabrication of the brightest source of entangled photon pairs to date (Nature 2010). The objective of the present project is to build up a platform for basic quantum operations using QDs in cavities. The first aim is to develop highly efficient light emitting devices emitting indistinguishable single photons and entangled photon pairs. The mechanisms leading to quantum decoherence in QD based sources will be investigated. We will also explore a new generation of devices where QDs are coupled to plasmonic nano-antenna. The second objective is to implement basic quantum operations ranging from entanglement purification to quantum teleportation using QD based sources. The third objective of the project is to control the spin-photon interface. We first aim at demonstrating quantum non-demolition spin measurement through highly sensitive off-resonant Faraday rotation. We then aim at entangling two spins separated by macroscopic distances, using their controlled interaction with photons. This will be obtained either by making a single photon interact with two spin in cavities or by interfering indistinguishable photons emitted by two independent charged QDs."

1 482 000 €

Start date: 2011-11-01, End date: 2016-10-31

Under high magnetic field and at low temperatures, electronic interactions in a two-dimensional electron gas give rise to exotic, strongly correlated many-body quantum Hall states. These states have been proposed for the implementation of new quantum circuits, for instance realizing topologically protected quantum computing. Although exciting, these states remain poorly understood, because the conventional experimental approach for their investigation, dc electron transport, only yields limited information. In particular, electron transport only probes the physics of the current-carrying edge channels of the quantum Hall effect propagating along the edges of the electron gas, leaving the physics of the bulk unexplored. To gain a better understanding of these exotic states and their origin, I propose a new, unconventional approach, based on heat transport measurements, which directly probes the charge-neutral, heat-carrying collective modes characterizing these interactions-induced states. I will focus on the debated ν=0 quantum Hall state of monolayer and bilayer graphene, which is thought to arise from spontaneous spin- and valley- symmetry breakings due to interactions, and on the fractional quantum Hall effect, where the competition between interaction and disorder gives rise to low-energy, heat-carrying neutral modes which have not yet been observed in graphene. Investigating the neutral modes through heat transport will address two important questions regarding these exotic new states: does ν=0 indeed arise from spontaneous symmetry breakings, and what is the origin of the low-energy neutral modes in the fractional quantum Hall effect, particularly in graphene. Furthermore, it will be possible to apply my approach to the investigation of other exotic quantum states in two-dimensions, such as the superfluid excitonic condensate in electron-hole bilayer systems.

1 499 839 €

Start date: 2019-02-01, End date: 2024-01-31

Electronic correlation causes a wide range of interesting phenomena, such as superconductivity or the fractional quantum hall effect. It strongly impacts our surroundings – think about defect creation through a self-trapped exciton, or, in the animal world, the adhesion of a gecko on a surface (through the van der Waals attraction). Although the underlying Coulomb interaction is « simple » and well understood, a unifying framework is still missing that would allow us to describe, analyze, understand and predict all those phenomena on the same footing. In this project we will introduce and establish a completely new method for the calculation of properties of correlated electron systems including ground state total energies, excitation spectra, electron-phonon coupling and non-equilibrium dynamics. The method is based on a non-perturbative solution of a multidimensional functional differential equation. This equation is the SEED from which distinct sub-lines of research will be grown. Based on my widely recognized experience in the field of many-body physics and starting from recent results of an exploratory study, the project will encircle the problem working on different levels of approximation, each of them introducing new physics. Thus every step along the project will allow us to tackle challenging questions, such as: “Does strong coupling in a material lead to new or exotic elementary excitations?” or “What can we say about multi - exciton generation, and how could it be tuned?”. These questions and our theoretical answers will be embedded in a tangible context through the study of emerging topics including Mott insulators and materials for photovoltaic applications. Each of these theoretical steps and planned applications carries the potential for breakthrough; together, they promise a seismic shift in our understanding of correlated processes and in our capability to predict new materials properties.

1 700 000 €

Start date: 2013-02-01, End date: 2018-01-31

Twenty-first century European husbandry results from thousand-year-old experiences. This project aims at giving a historical dimension to the growing questioning on present day herding practices among European consumers. Sheep, goat, cattle and pig were domesticated ca. 8500 cal. BC in the eastern Taurus. From there they spread to most of the Near East and entered Europe at the turn of the 7th millennium BC. They reached the North-western Europe coasts by the beginning of the 5th millennium and colonised the British islands during the 4th and 3rd millennia BC. Whereas domestication of European wild boar could have occurred, European aurochs did not contribute significantly to cattle populations. Sheep and goat do not have wild ancestors in Europe. Most of these animals actually stem from populations transferred from the Near East. The spread of domestic species outside the natural range of occurrence of their wild counterparts, their keeping in environmental settings different from their natural ecological niches, and the will to stimulate milk production in bovines and ovicaprines, imply some modifications in dietary and reproduction behaviours of domestic animals. Neolithic herders developed zootechnical skills to insure survival of their stock and the adaptation of their production strategies to new environments. The objective of this project is to evaluate the environmental and physiological constraints on the adaptation of stock keeping in Europe, and to determine to what extant Neolithic herders could modulate the biological system with technical choices. Landscape use, seasonal foddering, seasonality of birth and duration of lactation will be addressed using stable isotope analysis on animal bone and teeth. The animals stress condition will be assessed through analysis of enamel hypoplasia. The project includes Neolithic sites from Caucasia, Eastern, Central and Western Europe. It will necessitate methodological developments on modern reference skeletons.

883 802 €

Start date: 2008-10-01, End date: 2014-02-28

Compared to existing Random Access Memories, the Magnetic RAM (MRAM) has the advantage of being non-volatile. Though the basic requirements for reading and writing a single memory element are fulfilled, the present approach based on Spin Transfer Torque (STT) suffers from an innate lack of flexibility. The solution that I propose is based on the discovery of a novel phenomenon, where instead of transferring spin angular momentum from a neighbouring layer, magnetization reversal is achieved by angular momentum transfer directly from the crystal lattice. There is a long list of advantages that this novel approach has compared to STT, but the goal of this project is to focus only on their most generic difference: flexibility. The singularity of spin-orbit torque is that the in-plane current injection geometry decouples the “read” and “write” mechanisms. The disconnection is essential, as unlike STT where the pillar shape of the magnetic trilayer sets the current path, in the case of SOT the composing elements may be shaped separately. The liberty of shaping the current distribution allows to spatially modulate the torque exerted on the local magnetization. The central goal of my project is to explore the new magnetization dynamics, specific to the Spin-Orbit Torque (SOT) geometry, and design novel magnetization switching schemes. I will begin by tackling the fundamental questions about the origin of SOT and try to control it by mastering its dependence on the layer structure. Materials with on-demand SOT will serve as playground for the testing of a broad range of magnetization reversal techniques. The most successful among them will become the building-blocks of complex magnetic objects whose switching behaviour is tightly related to their shape. To study their magnetization dynamics I plan to build a time-resolved near-field magneto-optical microscope, a unique tool for the ultimate spatial and temporal resolution.

1 476 000 €

Start date: 2015-10-01, End date: 2020-09-30

"Materials where conduction electrons experience strong correlation in their dynamics, are both a challenge to the current quantum theories of matter and a mine for possible technological applications. High-temperature copper- and iron-based superconductors and heavy-fermions with large thermoelectric responses are examples of materials with high potential impact on energy transmission and storage technologies or high-magnetic field applications. Recently, the discovery that the well known atomic ""Hund's rules"" have a surprisingly great and diversified influence on the conduction electrons in d-electron materials changed the traditional view of electronic correlation as a competition between kinetic energy and Coulomb repulsion, adding Hund's exchange energy as a third axis. This project, by using state-of-the-art computational techniques for correlated materials, aims at clarifying the influence of the new Hund's driven mechanisms as possible enhancers of high-Tc superconductivity and of thermoelectric and thermomagnetic properties. In particular Hund's coupling can induce the coexistence of weakly and strongly correlated conduction electrons, culminating in orbital-selective Mott insulating states or in heavy-fermionic physics. We then aim at the creation of a new class of transition-metal (d-electron) compounds reproducing the properties of the more exotic rare-earth (f-electron) heavy-fermion materials, in a tunable way. Iron-based superconductors exhibit some of these properties and will be used as a starting point for the search and exploration of new and enhanced high-temperature superconductors and thermoelectric/thermomagnetic d-electron materials. An exciting application is also proposed, motivating a possible resurgence of technological attention towards thermomagnetic materials: the coating of high-power cables in thermomagnetic materials for self-cooling, and potentially room-temperature superconduction."

1 656 250 €

Start date: 2017-04-01, End date: 2022-03-31

This project aims at establishing the basis for high-temperature superconducting spintronics. The innovative idea is to use spin-polarized superconducting pairs -instead of normal electrons- to convey and manipulate information, taking advantage of the coherent transport inherent to superconductivity. To further increase the potential of this approach, we intend to create multiple control knobs: magnetic field, the classical one in spintronics, as well as the knobs customary in conventional electronics: electric field and light. This will endow superconducting spintronics with a magnetic and electric memory, as well as with photosensitivity. The basic ingredient for this ambitious project is complex-oxide heterostructures. The approach consists of combining the following fundamental effects: (a) Superconducting proximity effects, in order to transfer superconductivity into ferromagnets. (b) Ferroelectric field-effects, in order to modulate the superconductor/ferromagnet interactions and tune Josephson coupling. (c) Spin-torque and ferromagnetic resonance effects, in order to couple superconductivity and magnetization dynamics. (d) Photoconductivity and photoelectric effects, in order to manipulate the interactions between superconductors and ferroics. This research is essentially fundamental, but the novel concepts pursued will increase the technological possibilities of superconductivity and spintronics -whose applications are at present completely disconnected.

1 997 729 €

Start date: 2015-10-01, End date: 2020-09-30

"The aim of this project is to predict and compute extremely rare but essential trajectories in complex physical systems. We will compute rare transitions trajectories, first between two different turbulent attractors in models of planetary jet dynamics, and second between two configurations of ocean currents for a model of the thermohaline circulation. We will compute the dynamics and the probability for collisions between two planets in the solar system, on time scales of order of billions of years. We will evaluate rare events that lead to extremely large drags or torques on objects embedded in turbulent flows, directly from the dynamics. Because of the huge range of time scales, all those trajectories are not accessible through direct numerical simulations. The project's unity stems from the methodology based on large-deviations theory. Large deviation rate functions generalize the concept of entropy or free energy in non-equilibrium extended systems: they provide a global characterization of their most probable state, their large fluctuations and their phase transitions. Impressive explicit computations of large deviation rate functions have been recently performed in simple non-equilibrium systems. The main aim of this project is to bridge the gap between those extremely interesting new concepts and algorithms, and complex dynamical systems such as turbulent flows, semi-realistic models of fluids related to climate dynamics, or the long time behavior of the solar system. In order to achieve this goal, we will use macroscopic fluctuation theory, instanton theory, and other analytical methods in order to compute explicitly large deviation rate functions for essential macroscopic quantities (the velocity or density fields). We will also develop and use algorithms specifically dedicated at computing the statistics of extremely rare trajectories, based on the generalization of importance sampling implemented through cloning or multilevel splitting methods."

1 178 760 €

Start date: 2014-03-01, End date: 2019-02-28

The explanation for the distinct low temperature behavior of amorphous solids (glasses) is a long-standing open question. Specific puzzles include the nature of the low energy excitations (LEEs) that are responsible for their low temperature thermal and mechanical behavior and the origin of the remarkable universality of their low temperature mechanical dissipation. The phenomenological tunneling model proposes that the LEEs are atomic-scale tunneling two level systems (TLSs) and successfully explains much of the low temperature behavior of glass, but not the universality. Recently, individual TLSs were probed in the amorphous tunnel junction of superconducting qubits, but such dielectric measurements might not access the LEEs responsible for universality. In contrast, I propose to search for individual TLSs using purely mechanical measurements. The glass samples containing the TLSs will be nanomechanical resonators, and the strain coupling between the mechanical mode and the TLS will be used to control the quantum state of the latter. This strain coupling allows coherent state transfer between the mechanical mode and the TLS. Identifying individual TLSs and controlling their quantum state in this manner will demonstrate that the LEEs responsible for the characteristic low temperature properties of glass are indeed TLSs. Furthermore, these measurements will reveal the characteristics of individual TLSs and their interactions with their environment, in contrast to bulk measurements in which, according to the model, the effects of many TLSs are averaged. The results of the proposed study may therefore strongly support the tunneling model. This would require reconsideration of potential explanations for universality which are thought to be inconsistent with the existence of TLSs. Alternatively, if the hypothesized TLSs are absent, then the tunneling model must be replaced by a new interpretation of the low temperature properties of glass.

1 929 479 €

Start date: 2017-09-01, End date: 2022-08-31

Water is the most abundant liquid on Earth s surface. It is essential for life. Surprisingly, despite extensive studies, many of its properties remain to be explained. The aim of this project is to contribute to the understanding of water, by studying its anomalies in the metastable liquid state. A liquid should transform into vapour at its boiling point, or into a solid at its freezing point. However, it can be observed beyond these limits. It is then in a metastable state, separated from the stable phase by an energy barrier due to surface tension. The short lifetime of the liquid under such extreme conditions renders measurements particularly challenging. Nevertheless, we find them worth to undertake, because they will bring valuable information on its structure. Our proposal is twofold: in the negative pressure range, where the liquid is metastable with respect to the vapour, we will stretch water to a high degree by several methods, and measure the extension of its equation of state. This part is based on our knowledge of different techniques to obtain large negative pressures; we will use optical methods to access the physical properties. in the supercooled range, where the liquid is metastable with respect to the solid, we will develop new viscometers to measure the viscosity of supercooled liquid water under pressure. Our aim is not only to provide the missing viscosity data for supercooled water up to 300 MPa, but also to check its relation with translational and rotational diffusion, which can reveal a change in the liquid structure.

1 335 400 €

Start date: 2009-10-01, End date: 2015-09-30