29 novembre 2019
Collège de France
Fuseau horaire Europe/Paris

Liste des Contributions

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  1. Elisabeth Niel (LAL Orsay), Mayline Verguin, Nicolas DAGONEAU (CEA/Saclay - IRFU/DAp/LISIS)
    29/11/2019 09:30
  2. Rémy Thoer (csnsm)
    29/11/2019 09:40
    Physics
    Oral presentation

    Low Temperature Nuclear Orientation (LTNO) experiments allow to probe magnetic properties of polarized exotic nuclei. With this technique, we observe nuclei under extreme conditions, that is to say very low temperatures (~10mK) and very high magnetic field (10-100T). Under such conditions, the radioactive emission is anistropic, and its shape tells us more about the nucleus...

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  3. Simone Magaletti
    29/11/2019 10:00
    Physics
    Oral presentation

    The Nitrogen Vacancy (NV) centers are considered, for their optical and spin proprieties, promising candidates for quantum sensing applications. In this work, the spin-dependent optical proprieties of a NV centers ensemble are exploited in order to realize a spectrum analyzer.
    To do that, a static magnetic field gradient, generated by a permanent magnet, induces a spatial dependent Zeeman...

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  4. Louise Mousset (APC)
    29/11/2019 10:40
    Physics
    Oral presentation

    QUBIC is an experiment dedicated to the measurement of polarization B-modes of the Cosmic Microwave Background (CMB) using the novel technology of Bolometric Interferometry. In this talk, I will start with a brief explanation of the underlying physics: What are primordial B-modes and why it will give us invaluable insights on what happened during the inflation era, right after the Big Bang....

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  5. Dr Dario Dell'Arciprete (LPENS)
    29/11/2019 11:00
    Physics
    Oral presentation

    In nature, some motile microorganisms have evolved in such a way to respond to environmental light stimuli, essentially allowing them to find better living conditions.
    In the lab, it is possible to engineer bacterial cells so as to make them photokinetic, that is, to control their speed by means of the light shone on them: these cells move faster when exposed to high-intensity light, whereas...

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  6. Catherine Langlais (SFP)
    29/11/2019 11:20
  7. Dr Samuel Beaulieu (Fritz-Haber-Institute of the Max-Planck-Society)
    29/11/2019 11:30

    Chirality is a symmetry property of matter, which can emerge at any length scale, from galaxies to snail shells and even to subatomic particles. Chiral light-matter interactions have been investigated for two centuries, leading to the discovery of many chiroptical processes used for discrimination of enantiomers. Whereas most chiroptical effects result from a response of bound electrons,...

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  8. Nancy Paul (Laboratoire Kastler Brossel)
    29/11/2019 11:50

    Exotic, extremely radioactive nuclei play a key role in the nucleosynthesis processes responsible for heavy element production in cataclysmic events in the universe, such as recently observed in the binary neutron star merger detected via gravitational waves [1] . The nucleosynthesis yields depend on the details of the underlying quantum structure of these nuclei, largely unknown as such...

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  9. Fabrice Desse (LAL Orsay)
    29/11/2019 14:00
    Physics
    Oral presentation

    The conflicts between cosmological observations (dark matter, matter/anti-matter asymmetry ...) and the predictions of the Standard Model (SM) calls for New Physics (NP) beyond the SM, i.e. new interactions or new particles. Collider experiments such as the LHC at CERN is a privileged place for NP searches. Indeed, by smashing together two protons at nearly the speed of light, one can try to...

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  10. Dr Filippo Vicentini (Université Paris Diderot - Laboratoire MPQ)
    29/11/2019 14:20
    Physics
    Oral presentation

    The state of a quantum system is completely determined by its wave-function or density-matrix, which evolve according to an equation of motion. When the system is composed of many interacting particles, the many-body problem increases exponentially the size of those objects, which eventually cannot be stored in the memory of a computer. For decades researchers approached the issue by...

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  11. Marion Lehuraux (CEA Saclay)
    29/11/2019 14:40
    Physics
    Oral presentation

    Muon tomography consists in using cosmic muons to probe structures in a non-invasive nor destructive way. The successful development of muon telescopes using Micro-Pattern Gaseous Detectors over the past decades triggered the interest of many industrials for such technology. However, telescopes are limited in terms of compacity and angular acceptance which are performances with high...

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  12. Maxime Garnier
    29/11/2019 15:15
    Physics
    Oral presentation

    The Majorana fermion, initially theoricized in high-energy physics, has the particularity of being its own antiparticle. In 2001, Kitaev [1] proposed that Majoranas could be realized as low energy excitation in something called a topological superconductor triggering a huge number of theoretical and experimental studies, especially due to interesting possibilities in quantum computing....

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  13. Ariane GAYOUT (Laboratoire de Physique - ENS de Lyon)
    29/11/2019 15:35
    Physics
    Oral presentation

    Fluid-structure interactions are the basics of the complexity of Aerodynamics, enhancing resonance in structures and turbulence in flows. Even simple systems like a pendulum can become more complex, as a hysteretic bistability shows up for a range of flow velocities when the pendulum confronts a flow. This is predicted by a simple balance of weight and aerodynamical forces, but non stationary...

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  14. Mathieu Isoard (LPTMS)
    29/11/2019 15:55
    Physics
    Oral presentation

    Black holes are intriguing and singular objects; Einstein did not even believe in their existence. However, the first observation of a rotating black hole in our universe has been recently reported and is an undeniable confirmation of their presence.

    In 1974, Hawking predicted that black holes are not completely black, but emit a thermal radiation at a certain temperature $T_{\rm H}$, the...

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  15. Catherine Nguyen (Laboratoire APC/ Université Paris-Diderot)
    29/11/2019 16:30
    Physics
    Oral presentation

    Gravitational waves (GW) are ripples in the fabric of spacetime, emitted by compact accelerating objects. On September 2015, the first direct detection of GW from a binary black hole merger initiates the field of GW astronomy and opened a new window on the Universe. On August 17, 2017, Advanced LIGO and Advanced Virgo detectors jointly detected gravitational-waves resulting of the merger of...

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  16. Felipe Garcia (LLR, LAL)
    29/11/2019 16:50
    Physics
    Oral presentation

    Quarkonia, bound states between a heavy quark and its own antiquark, are of particular interest when it comes to probing the Quark Gluon Plasma (QGP), a very special state of matter believed to have been in existence during the first moments after the Big-Bang. This state of matter can be recreated in high energy heavy ion collisions and one of the ways it can be studied, is through the...

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  17. Simon Vincent (Laboratoire de Physique - ENS de Lyon)
    29/11/2019 17:10
    Physics
    Oral presentation

    Low frequency waves turbulence developing in magnetized plasma columns are well known to trigger important radial transport, a major issue for fusion devices. We present here analysis from very fast imaging of low frequency waves in a magnetically confined plasma column.

    Our experimental set-up consists in a cylindrical chamber containing an Argon plasma column of 10 cm diameter of...

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  18. M. Baldo Luis Najera-Santos (Laboratoire Kastler Brossel)
    Physics
    Poster

    Quantum thermodynamics follows the approach of classical thermodynamics to study the energy exchange during the interaction of quantum systems. It defines the quantum counterparts of heat, work, and entropy, and it provides equations that constrain the variation of these quantities. The Maxwell's demon Gedankenexperiment portrays a tiny being that uses the information on individual molecules...

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  19. Valentin Métillon (LKB - Collège de France)
    Physics
    Poster

    Cavity quantum electrodynamics (CQED) is a field where the emission properties of atomes are modified by coupling with modes of cavities. Using Rydberg atoms coupled with ultra high finesse microwave cavities, the CQED team of LKB achieved a strong coupling regime, where the interaction of atoms with light is much stronger than decoherence. The very long life-time of the cavities made it...

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  20. Dr Tommaso Morresi (Sorbonne Université, UPMC)
    Physics
    Poster

    The aim of this work is the calculation of vibrational properties of hydrogen-rich materials where Nuclear Quantum Effects play an important role. The computational methods are based on Molecular Dynamics simulations combined with Quantum Monte Carlo (QMC) for the electronic part and a Langevin thermostat correlated according to the covariance matrix of QMC nuclear forces. In particular, we...

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  21. Zhibo Wu
    Physics
    Poster

    The steadily increasing luminosity of LHC requires an upgrade to high rate and high-resolution capable detector technology for the inner end cap of the muon spectrometer of the ATLAS experiment. For precision tracking, large area Micromegas quadruplets are produced, in order to provide 8 consecutive active layers with 100 micron spatial resolution per individual plane. As for validation of the...

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  22. Maxence Revolle (CEA Saclay)
    Physics
    Poster

    Micro-Pattern Gas Detectors (MPGD) are now commonly used in particle physics experiences (COMPASS,ALICE,ATLAS...), mainly as a particle tracker. For the new Electron Ion Collider (EIC) in the USA, planned for 2030, a collaboration between CEA-Saclay, Brookhaven National Laboratory and Stony Brooks University have been created with the goal of improving MPGDs based tracking chambers. By using...

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  23. M. Hugo Jonquiere (ONERA)
    Physics
    Poster

    La complexité des optiques spatiales va croissante (Projet ELT : 981 segments de 1.5 m de diamètre, de formes différentes, Miroirs free-form, etc...) tandis que dans le même temps, les cadences de production s’accélèrent (Exemple : Projet ELT : 3 ans pour produire 981 segments).
    Les gammes d’instruments métrologiques doivent s’adapter et requièrent des solutions industrielles performantes et...

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  24. Marc Arène (APC)
    Physics
    Poster

    Gravitational waves are ripples of space time typically produced by inspiraling pairs of neutron stars and/or black holes, our sources. Once detected by the ground-based LIGO and Virgo interferometers, the next step is to estimate the parameters of these sources such as their distance, localization in the sky, masses of each component etc.

    This task is currently carried out by MCMC...

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  25. Peng PAN (ISMO-CNRS-UniversitéPariSaclay)
    Physics
    Poster

    Schematic representation of grazing incidence diffraction (GIFAD) discovered in the group by Patrick Rousseau. At grazing incidence, the fast He projectile with keV energy is diffracted by the well-ordered rows of atoms by successive gentle collisions. The He projectile is repelled by the surface electronic density so that GIFAD can be seen as a helium tip AFM operated in the reciprocal...

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  26. Aishik Ghosh (LAL)
    Physics
    Poster

    Accurate simulations of a showers from particles from the Large Hadron Collider in the ATLAS calorimeter are incredibly resource intensive, consuming the largest fraction of CPU time on the CERN computing grid. Generative Adversarial Networks are investigated as a scalable solution for modelling the response of the electromagnetic calorimeter for photons over a range of energies. Steps have...

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  27. M. Mathieu LE VERGE SERANDOUR (Collège de France)
    Physics
    Poster

    We investigate the role of cell contractility and molecular adhesion in the formation of the blastocoel during early mouse embryo development, a fluid-filled lumen that positions the first axis of symmetry of the embryo. We show that hundreds of micron-sized fluid filled cavities appear throughout the entire embryo on basolateral (adhesive) sides of cells, fracking cell-cell contacts. Via a...

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  28. Osmin Lacombe
    Physics
    Poster

    Supersymmetry (SUSY) was first introduced to address unanswered aspects of the Standard Model of particle physics such as the unification of gauge couplings at high energies. It then proved useful in broader theoretical contexts, from string theory to dark-matter models. SUSY assumes the existence of N symmetries relating fermionic and bosonic fields. When N>1, it is referred to as...

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  29. Nicolas Baillot d'Etivaux (IPN Lyon)
    Physics
    Poster

    In the last decades, nuclear equation of state has been a dealing problem. Measuring neutron stars (NSs) radii can bring a key information on nuclear matter properties at very high densities. We employ an empirical parameterization of the equation of state with a Markov-Chain Monte Carlo approach in a Bayesian framework, to consistently fit the spectra of 7 selected NSs. Despite previous...

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  30. M. Saroch Leedumrongwatthanakun (LKB, Département de Physique, Ecole Normale Supérieure)
    Physics
    Poster

    High-speed data transfer through optical fibres using spatial multiplexing is practically limited by modal crosstalk. Instead of considering this modal crosstalk as a limitation, we here harness its mode mixing to process quantum optical information. We implement a programmable linear optical network based on the concept of inverse photonic design exploiting the technology of wavefront...

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  31. Hugo Perrin
    Physics
    Poster

    Quantum walks can be seen as the quantum counterpart of the classical random walk on lattice. They lead to a dynamic which is very different from the tight binding hamiltonian framework and its schrodinger equation. Other features from both systems can be compared and I mainly focus on the effect of a transverse magnetic field to the lattice. In the hamiltonian case, when we plot the...

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  32. Hamza El Bouhargani (AstroParticle and Cosmology laboratory (APC))
    Physics
    Poster

    Inflation theories elegantly address a number of problems raised by the standard Hot Big Bang scenario, however one of its major predictions, the existence of a stochastic background of cosmological gravitational waves, is yet to be confirmed. Currently the most promising, if not the only, way to achieving this is through the observation of the Cosmic Microwave Background (CMB) polarization....

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  33. Lina HOUMMI (University of Liverpool/Synchrotron SOLEIL)
    Physics
    Poster

    The SOLEIL synchrotron is the French national third generation light source storage ring, which provides photon beams to 29 beamlines from infrared to hard X-rays. Future synchrotron sources aim at increasing the brilliance by decreasing the electron beam emittance, down to the natural diffraction limit: they are Diffraction Limited Storage Rings (DLSRs). In order to improve its performance...

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  34. Ayoub Aouina (LSI)
    Physics
    Poster

    In material science we often use model systems to describe real materials. In this talk we are interested in the question of how to import, in principle exactly, a quantity of interest from a model into a real system. The prescription how to do that is what we call "connector theory" [1]. An enormous advantage of this strategy is that model results can be obtained once forever and tabulated....

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  35. Gregory PAGE (LPTMC)
    Physics
    Poster

    A new class of 2D billiards, defined by a unit circle enclosing a geometrically variable, central scattering ellipse is introduced.

    The system exhibits mixed dynamics which is explored via Recurrence plots (RPs) and the associated recurrence quantification analysis (RQA), with a focus on long-term motion starting from the unstable period 2 orbit.

    The main result shows the existence of a...

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  36. Dr Soufiya MIZANI (1Laboratory of condensed matter, faculty of sciences Ben M`sick (URAC.10). University Hassan II of Casablanca, Morocco), Dr Hicham ZERRADI (1Laboratory of condensed matter, faculty of sciences Ben M`sick (URAC.10). University Hassan II of Casablanca, Morocco), Prof. Aouatif DEZAIRI (1Laboratory of condensed matter, faculty of sciences Ben M`sick (URAC.10). University Hassan II of Casablanca, Morocco)
    Physics
    Poster

    the Experimental and theoretical research related to improving the transfer of A number of authors have carried out heat using nanoparticles and their results showed that the heat transfer of nanofluids is very important in this context our work presents a critical model for improved heat transfer This work is done on the basis of a 2D numerical dimension of heat transport models, which can be...

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  37. M. Francesco Mori (LPTMS, Université Paris-Sud)
    Physics
    Poster

    The properties of extremes of a stochastic process/time series of a given duration $T$ are of fundamental importance in describing a plethora of natural phenomena. For example, this time series may represent the amplitude of earthquakes in a specific seismic region, the amount of yearly rainfall in a given area, the temperature records in a given weather station, etc. The study of extremes in...

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  38. Armand Barbot (PMMH, CNRS UMR 7636, ESPCI Paris, PSL University, Sorbonne Université, Université de Paris, F-75005 Paris, France)
    Physics
    Poster

    Many phenomena remain poorly understood in amorphous materials such as plasticity and shear banding, their brittleness and disordered structure making it difficult to study them experimentally. As a consequence, we use model two-dimensional Lennard-Jones glasses and measure their local yield stress, a measure of the local softness, as presented in [1]. This method is nonperturbative and is...

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