Matériaux et Phénomènes Quantiques

MPQ

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Université Paris Diderot

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UFR Physique

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UMR

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CNRS

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-01440799] Thermodynamics of Pd(-Au) nanoparticle-titania interface studied by aberration-corrected TEM

Date: 24 sep 2022 - 16:44

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[hal-01369887] Determining the energetics of supported bimetallic au-pd nanoparticles by aberration-corrected tem

Date: 24 sep 2022 - 16:44

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

Date: 24 sep 2022 - 15:58

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: 24 sep 2022 - 15:58

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

[hal-01987566] Interplay between interfacial and structural properties on the magnetism of self-organized core-shell Co/Pt supported nanodots

Date: 18 sep 2022 - 04:59

Desc: We have studied the influence of Pt capping on the magnetic properties of self-organized Co nanodots by means of complementary structural and magnetic investigation techniques. The growth of monodisperse 5 nm diameter Co dots on a Au(111) surface and its progressive coverage by Pt were performed under ultrahigh vacuum conditions and imaged by scanning tunneling microscopy, revealing a weak mixing at room temperature. The Co/Pt core-shell structure was studied both by molecular-dynamics simulations and surface extended x-ray-absorption fine structure, showing a global dilatation of the Co core. Both magnetic moments and hysteresis cycles at various temperatures were measured using x-ray magnetic circular dichroism, revealing a slight increase of the magnetic moments and the out-of-plane magnetic anisotropy after Pt capping. Moreover, the variation of magnetic anisotropy as a function of capping was followed in situ by the magneto-optical Kerr effect. Our investigations demonstrate that interfacial hybridization between Co and Pt is dominant over magnetoelastic contribution in this system.