Matériaux et Phénomènes Quantiques
Présentation
Le laboratoire Matériaux et Phénomènes Quantiques (MPQ) est une unité mixte de recherche (UMR 7162) du CNRS et de l’Université Paris Diderot, installée sur le campus de Paris Rive Gauche. Elle est composée d’environ 120 personnes au total dont 51 permanent.e.s.
Le laboratoire est spécialisé dans l’étude des matériaux quantiques de frontière et dans le développement de dispositifs quantiques innovants. Ces activités reposent sur un large spectre de compétences théoriques et expérimentales alliant la physique des matériaux, le transport et l’optique, et des plateformes technologiques de salle blanche, de spectroscopie et de microscopie électronique haute résolution.
Les activités de recherche du laboratoire MPQ se déclinent selon les thèmes suivants :
- nouveaux matériaux à l’échelle nano : nanoparticules, nanocristaux, nanotubes fonctionnalisés, matériaux multiferroïques, etc.
- nouveaux états de la matière : fluides quantiques de lumière, couplage ultra-fort en cavité, supraconducteurs non-conventionnels, systèmes fortement corrélés, phases topologiques, etc.
- systèmes nano-optiques innovants : optomécanique, nanophotonique non-linéaire, nanoplasmonique, etc.
- ingénierie quantique et information quantique : composants optoélectroniques quantiques, circuits photoniques quantiques, ions piégés, matériaux et composants hybrides organique/inorganique, ingénierie des surfaces/interfaces.
Les projets actuels du laboratoire incluent le développement de nouvelles sondes pour l’étude des matériaux quantiques, comme la spectroscopie Raman résolue en temps, la microscopie AFM opto-mécanique et la microscopie tunnel sous excitation optique. Réciproquement, les matériaux de frontière sont mis à profit pour la réalisation de nouvelles fonctionnalités dans des senseurs optomécaniques, des circuits photoniques non-linéaires et quantiques, ou encore dans des expériences de transport mésoscopique en cavité optique.
[hal-02273489] Mixing properties of room temperature patch-antenna receivers in a mid-infrared ($\lambda$ $\sim$ 9$\mu$m) heterodyne system
Date: 12 mai 2021 - 04:39
Desc: A room-temperature mid-infrared (9 um) heterodyne system based on high-performance unipolar optoelectronic devices is presented. The local oscillator (LO) is a quantum cascade laser, while the receiver is an antenna coupled quantum well infrared photodetector optimized to operate in a microcavity configuration. Measurements of the saturation intensity show that these receivers have a linear response up to very high optical power, an essential feature for heterodyne detection. By an accurate passive stabilization of the local oscillator and minimizing the optical feed-back the system reaches, at room temperature, a record value of noise equivalent power of 30 pW at 9um. Finally, it is demonstrated that the injection of microwave signal into our receivers shifts the heterodyne beating over the bandwidth of the devices. This mixing property is a unique valuable function of these devices for signal treatment.
[hal-02166303] Symmetry of the Excitations in the Hidden Order State of URu 2 Si 2
Date: 12 mai 2021 - 04:39
Desc: [...]
[hal-02459857] Full exact solution of the out-of-equilibrium boundary sine Gordon model
Date: 12 mai 2021 - 04:27
Desc: The massless boundary sine-Gordon (SG) model is the only interacting impurity model with a known exact solution out-of-equilibrium, yet existing so far only for integer values of the sine Gordon coupling $\lambda$ [Phys. Rev. Lett. {\bf74}, 3005 (1995)]. We present here a full exact solution for arbitrary rational values of $\lambda$, at arbitrary voltage $V$ and temperature $T$. We use the "string" solutions of the bulk SG model, here regarded as genuine quasiparticles avoiding charge diffusion in momentum space. We carefully present the finite voltage and temperature thermodynamics of this gas of interacting exotic quasiparticles, whose very nature depends on subtle arithmetic properties of the rational SG parameter $\lambda$, and explicitly check that the string representation is thermodynamically complete. By considering a Loschmidt echo, we derive the exact transmission probability of strings on the impurity. We obtain the exact universal scaling function for the electrical current $I(V,T)$. Our results are in excellent agreement with recent experimental out-of-equilibrium data and question the reality of these exotic quasiparticles.
[hal-02467226] Universality at work – the local sine-Gordon model, lattice fermions, and quantum circuits
Date: 11 mai 2021 - 23:48
Desc: We review the intriguing many-body physics resulting out of the interplay of a single, local impurity and the two-particle interaction in a one-dimensional Fermi system. Even if the underlying homogeneous correlated system is taken to be metallic, this interplay leads to an emergent quantum phase transition between metallic and insulating states. We show that the zero temperature critical point and the universal low-energy physics associated to it, is realized in two different models, the field theoretical local sine-Gordon model and spinless fermions on a lattice with nearest-neighbor hopping and two-particle interaction, as well as in an experimental setup consisting of a highly tunable quantum circuit. Despite the different high-energy physics of the three systems the universal low-energy scaling curves of the conductance as a function of temperature agree up to a very high precision without any free parameter. Overall this provides a convincing example of how emergent universality in complex systems originating from a common underlying quantum critical point establishes a bridge between different fields of physics. In our case between field theory, quantum many-body theory of correlated Fermi systems, and experimental circuit quantum electrodynamics.
[hal-01971706] Gas-induced selective re-orientation of Au-Cu nanoparticles on TiO 2 (110)
Date: 11 mai 2021 - 12:37
Desc: Au-Cu bimetallic nanoparticles (NPs) grown on TiO 2 (110) have been followed in-situ using grazing incidence x-ray diffraction and x-ray photoemission spectroscopy from their synthesis to their exposure to a CO/O 2 mixture at low pressure (P < 10-5 mbar) and at different temperatures (300 K-470 K). As-prepared samples are composed of two types of alloyed NPs: randomly oriented and
Autres contacts
Université Paris Diderot - Paris 7
U.F.R. Physique
Bâtiment Condorcet
10, rue Alice Domon et Léonie Duquet
75205 PARIS CEDEX 13
