Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Russia

报告人简介

Dr. Victor Solovyev is currently a Senior Researcher at Institute of Solid State Physics, Russian Academy of Sciences (ISSP-RAS), Chernogolovka, Russia. He studied at Moscow Institute of Physics and Technology and earned his BS/MS degrees in physics by 2007, followed by his PhD in Condensed Matter Physics completed by 2011 after working with Prof. Igor Kukushkin at ISSP-RAS, in a close cooperation with colleagues of the Institute for Solid State Research, Max Planck Institute (MPI-FKF) in Stuttgart, Germany).

报告摘要

The path to understanding the structure and properties of strongly correlated many-particle systems began more than a century ago with the theories of heavy atoms and nuclei, continued in various aspects of condensed matter physics, and received a new bright and continuing impulse with the development of two-dimensional electronic systems of exceptional quality. Currently, most experimental results on electronic properties are obtained using transport techniques, which provide information about the structure of the energy spectrum of excitations of systems only near the Fermi surface.

This talk highlights recent results of magneto-optical studies of strongly correlated electronic systems in ZnO/MgZnO and GaN/AlGaN heterostructures. The large band gap in these materials contributes to an increased mass of charge carriers and a reduced dielectric constant of the medium compared to the prototypical GaAs/AlGaAs system, which together favors the enhanced manifestation of Coulomb correlations in electronic properties. In contrast to transport studies, optical spectroscopy allows one to study a special class of excitations of an electronic system - quasi-holes - over the entire range of their possible energies. The main part of the report is devoted to the concept of the Mahan exciton, a Coulomb-bound state of a single free valence hole and a Fermi collective of electrons. First proposed more than half a century ago, it has finally received clear experimental confirmation in the striking features of the photoluminescence spectra from wide-gap heterostructures. Unexpected and partly hitherto unexplained properties of optical spectra are emphasized, as well as open conceptual questions about the structure of the bound state.

The talk concludes with a brief overview of significant expansions of the optical spectroscopy capabilities when combined with excitation by microwave radiation resonant with either feature of the electronic energy spectrum.

地点： M255会议室

邀请人：李永庆 研究员

联系人：孙丽（18601300418）

主办单位： 应用物理中心