The main direction of the laboratory activity is the experimental and theoretical study of quantum response in condensed nanostructured media generated by a variety of nanotechnological methods based on semiconductor, superconductor and ferromagnetic materials. In particular, here we deal with such media as graphene, topological insulators and two-dimensional semimetal that have been discovered in the first decade of this century. The study of which is currently the most rapidly growing area of condensed matter physics. A number of new quantum phenomena such as: the quantum Hall effect and mecha-scopic effects as well as the quantum spin Hall effect and quantum nonequilibrium effects in two-dimensional electron gas with a large number of Landau levels, have been discovered in these systems in the last few decades.
The laboratory of quantum phenomena in condensed media occupies one of the leading positions in the related field of physics. In recent years, the most important part of the laboratory activity is focused on determining the basic quantum properties of two-dimensional and three-dimensional topological insulators based on mercury telluride (HgTe), and discovering new non-trivial properties of Dirac fermions in graphene, as well as on establishing the characteristics of oscillations magnetoresistance induced by terahertz radiation that has been recently discovered in the laboratory in collaboration with Regensburgs university.
The main achievement of the laboratory is a series of works, where a number of interesting properties of topological insulators (TI) - a new class of solids, the principal feature of which is the simultaneous existence of the dielectric and metallic state has been described for the first time. A three-dimensional topological insulators on the basis of stress HgTe having high electron and hole mobility has been developed. Due to such high mobility the complete information about the transport properties of TI in the transition zones of the Fermi level from the bulk area to the surface states area has been obtained for the first time. Moreover, thanks to the fact mentioned-above a two-dimensional TI has been implemented for the first time, showing the effect of the backscattering topological protection at unusually long distances.
During the experiments, the quantization of the Hall resistance at liquid nitrogen temperatures in the two-dimensional electron systems based on semiconductors has been observed for the first time in the laboratory. The importance of such effect implementation at liquid nitrogen temperature is associated with the development of the standard resistance, capable of operating at temperatures the preparation of which does not require the use of super-expensive liquid helium, but of much cheaper nitrogen.
Together with the University of Regensburgs (Regensburg, Germany) for the first time a detailed experimental study of the photovoltaic effect in HgTe quantum wells has been conducted. It was found that this effect is caused by the oscillations of the spin polarization and the electron mobility in the spin subbands.
The academic laboratory has been created at the Section of semiconductor physics and conducts research in collaboration with the Institute of Semiconductor Physics named after A.V. Rzhanov SB RAS.
International partners of the Laboratory: Regensburg University (Germany), GHMFL (France), University of Sao-Paolo (Brasil).
Expert: Doctor in Physics and Mathematics, Professor Kwon Ze Dong (firstname.lastname@example.org)