Création et contrôle des systèmes d'électrons à deux dimensions corrélées

par Ji Dai

Projet de thèse en Physique

Sous la direction de Andres Santander.

Thèses en préparation à Paris Saclay , dans le cadre de École doctorale Physique en Île-de-France (Paris) , en partenariat avec Centre de sciences nucléaires et de sciences de la matière (Orsay, Essonne) (laboratoire) et de Université Paris-Sud (établissement de préparation de la thèse) depuis le 01-10-2016 .

  • Titre traduit

    Creation and control of correlated two-dimensional electron systems

  • Résumé

    In solids, the breaking of symmetry at surfaces or interfaces can lead to a reconstruction of the electronic structure and the emergence of novel phenomena of fundamental and applied importance. Paradigmatic examples are the quantum Hall effect, the spin-polarized Dirac-cone states in topological insulators, or the two-dimensional electron gases at semiconductor interfaces, which are at the basis of modern electronics. Recently, we discovered that metallic two-dimensional electron states can be created at the surface of transparent insulating transition-metal oxides. This is appealing, as these materials are often strongly-correlated electron systems presenting remarkable behavior, such as high temperature superconductivity, colossal magnetoresistance, or photocatalytic capacity. Thus, several of these oxides could also develop, at their surfaces, 2D electron gases with exotic properties, opening fascinating perspectives for fundamental studies of correlated electron systems and for oxide-based electronics, or “OXITRONICS”, one of the most active areas of research in today's Condensed-Matter Physics. At present, we are investigating the creation and control of 2D electron states at the surface of different correlated-electron oxides. As part of this activity, we are assembling a lab-based high-resolution ARPES systems coupled to a chamber for thin-film growth. This setup will be used to directly fabricate the 2D electron states, tailor their microscopic properties, and study their electronic structure. This work benefits from strong experimental and theoretical collaborations with other laboratories at Université Paris-Sud: Laboratoire de Physique de Solides, Thales-Lab, and Institut d'Electronique Fondamentale.