Open RQC colloquium. Lecture 33

Abstract

Studies of non-trivial topological phases of semiconductor materials such as 3D topological insulators, topological crystalline insulators, Dirac semimetals, Weyl semimetals – are one of the rapidly developing fields of the modern solid state physics. By now, the main tools of this research are ARPES measurements. On the other hand, studies of the electron transport via these states still remain a challenge. We have studied 3D topological insulators, topological crystalline insulators and Dirac semimetals using the photoelectromagnetic effect induced by strong terahertz laser pulses. It is demonstrated that the photoelectromagnetic effect features change upon the transition between the topologically trivial and non-trivial phases of the topological insulators and Dirac semimetals induced by the alloy composition variation. It is shown that thermalization of the photoexcited electrons is strongly damped in the topologically non-trivial phase compared to the trivial phase. A mechanism assuming existence of a spin texture on the surface of the topologically non-trivial phases is suggested.

Biography

Professor Dmitry Khokhlov is a Head of the Chair of General Physics and Condensed Matter Physics at the Physics Department of the M.V. Lomonosov Moscow State University since 2006. He was graduated from the Physics Department of the M.V. Lomonosov Moscow State University in 1980, and after that got his PhD (1982) and Doctor of Science (1992) degrees from the same university. Since 1982, he works at the Physics Department of the M.V. Lomonosov Moscow State University at positions from Junior Research Fellow to Professor, Head of the Chair. In 2008, he was elected a Correspondent Member of the Russian Academy of Sciences. His research interests are related to studies of narrow-gap semiconductor materials, development of sensitive detectors of terahertz radiation, studies of resistive switching effects in organic semiconductors, terahertz photoelectric phenomena in topological insulators.

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