Matériaux et Phénomènes Quantiques

MPQ

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Université Paris Diderot

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UFR Physique

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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-01944732] Demonstration of an Effective Ultrastrong Coupling between Two Oscillators

Date: 4 déc 2018 - 18:55

Desc: When the coupling rate between two quantum systems becomes as large as their characteristic frequencies, it induces dramatic effects on their dynamics and even on the nature of their ground state. The case of a qubit coupled to a harmonic oscillator in this ultrastrong coupling regime has been investigated theoretically and experimentally. Here, we explore the case of two harmonic oscillators in the ultrastrong coupling regime. Probing the properties of their ground state remains out of reach in natural implementations. Therefore, we have realized an analog quantum simulation of this coupled system by dual frequency pumping a nonlinear superconducting circuit. The pump amplitudes directly tune the effective coupling rate. We observe spectroscopic signature of a mode hybridization that is characteristic of the ultrastrong coupling. We experimentally demonstrate a key property of the ground state of this simulated ultrastrong coupling between modes by observing simultaneous single- and two-mode squeezing of the radiated field below vacuum fluctuations.

[hal-01793753] Towards the experimental demonstration of quantum radiation pressure noise

Date: 16 mai 2018 - 22:02

Desc: [...]

[hal-02100722] III-nitride on silicon electrically injected microrings for nanophotonic circuits

Date: 16 avr 2019 - 11:59

Desc: Nanophotonic circuits using group III-nitrides on silicon are still lacking one key component: efficient electrical injection. In this paper we demonstrate an electrical injection scheme using a metal microbridge contact in thin III-nitride on silicon mushroom-type microrings that is compatible with integrated nanophotonic circuits with the goal of achieving electrically injected lasing. Using a central buried n-contact to bypass the insulating buffer layers, we are able to underetch the microring, which is essential for maintaining vertical confinement in a thin disk. We demonstrate direct current room-temperature electroluminescence with 440 mW/cm 2 output power density at 20 mA from such microrings with diameters of 30 to 50 µm. The first steps towards achieving an integrated photonic circuit are demonstrated.

[hal-02500531] Epitaxial diamond on Ir/ SrTiO3/Si (001): From sequential material characterizations to fabrication of lateral Schottky diodes

Date: 19 Mar 2020 - 16:44

Desc: Advanced characterizations with combined analytical tools were carried out at the different stages of diamond heteroepitaxy on Ir/STO/Si (001) substrates. HRTEM and STEM-EELS revealed the presence of epitaxial nanometric diamond crystals after bias enhanced nucleation. UV Raman allowed estimating the diamond film quality and its strain at the early stages of heteroepitaxial growth. The crystalline structure and the strain within thick heteroepitaxial films were determined by XRD and CL investigations. A CL study of the cross-section provided the mapping of the dislocation network along the growth direction. Measurements performed on lateral Schottky diodes fabricated on a thick diamond film showed an excellent reproducibility on the substrate with a Schottky barrier height in good agreement with those obtained on homoepitaxial layers.

[hal-01965435] Diamond heteroepitaxy on Ir / SrTiO3 / Si (001) substrates: from nucleation to thick films characterizations

Date: 26 déc 2018 - 08:58

Desc: The up-scaling of heteroepitaxial diamond remains one challenge for the development of power electronics. One option is to consider heterosubstrates compatible with silicon based technologies, such as Ir / YSZ / Si [1]. We have developed diamond heteroepitaxy on iridium buffer layers grown on SrTiO3 / Si (001) [2]. The SrTiO3 has a low lattice mismatch with Ir (1.7 %) whereas the silicon substrate ensures a closer thermal expansion mismatch with diamond. This study provides an extended characterization of the heteroepitaxial process on SrTiO3 / Si (001): from the iridium deposition, to the bias enhanced nucleation (BEN) and the growth of heteroepitaxial diamond films (200 nm up to 240 m thick). High quality iridium buffer layers were grown on SrTiO3 / Si (001) with mosaicities of 0.3° (polar) and 0.1° (azimuthal) according to XRD. After the BEN step, the surface and the interfaces of Ir / SrTiO3 / Si (001) multilayer were investigated by SEM and HRTEM in cross-section. The morphology and the crystalline quality of a 200 nm thick heteroepitaxial diamond film were characterized using SEM and UV Raman. A cross-section of this film was investigated by High Resolution TEM. Thicker diamond films were grown under MPCVD growth conditions close to homoepitaxy [3]. Structural and chemical characterizations of diamond heteroepitaxial films grown on Ir / SrTiO3 / Si (001) were performed by XRD, Raman and Cathodoluminescence. The obtained results demonstrate the potential of Ir / SrTiO3 / Si (001) to achieve heteroepitaxial diamond films with characteristics at the state-of-the-art. The up-scaling has already proved successful allowing the substrate size to be increased from 5x5 to 7x7 mm2. References [1] M. Schreck et al., MRS Bulletin 39 (2014) 504 [2] K. H. Lee et al., Diam. Relat. Mater. 66 (2016) 67. [3] J. Achard et al., J. Phys. D, 40 (2007) 6175