Specialization: 011200 Physics
Program: Electronics of Nanosystems
Program manager: Prof. Dr. A. S. Shulakov
Department of Solid State Electronics 
Supervisor: Prof. Dr. A. M. Shikin
Referee: Prof. Dr. G. G. Vladimirov

Investigation of the spin electronic and atomic structure of topological insulators with different stoichiometry for the generation of spin currents
M.V. Filianina

Topological insulators (TIs) have attracted a lot of interest in recent years as being a promising material for spintronics application. Generation of spin-polarized currents is possible in TIs because of spin-momentum locking for the topologically-protected surface states (TSSs). Searching for new topological compounds with demanded features of electronic structure is an ongoing problem of spintronics. 
In this work we investigate spin and electronic structure of several TIs Bi1.5Sb0.5Te1.8Se1.2,  PbBi2Se2Te2,  PbBi4Te4Se3,  and PbBi4Te5Se2 experimentally using Spin- and Angle-Resolved Photoelectron Spectroscopy (spin-ARPES). We analyze the features of TSSs which are responsible for effective spin currents formation. We experimentally demonstrate the existence of large circular dichroic Fermi level shifts in ARPES spectra of Bi1.5Sb0.5Te1.8Se1.2 and relatively small shifts for PbBi2Se2Te2. We propose an explanation for these shifts in terms of the spin-asymmetric depletion of carriers within the light spot, which in turn results in a spin-polarized compensating charge current.
The list of publications:
1) M. Rusinova, I.I. Klimovskikh., A.A. Rybkina, A.G. Rybkin, E.V. Zhizhin, A.M. Shikin “Spin structure in thin Au layers on W(110) and Mo(110)”, Book of Abstracts, Proceedings "Science and progress" p. 58, St. Petersburg State University, 2013.
2) A.M. Shikin, A.A. Rybkina, I.I. Klimovskikh, M.V. Rusinova, E.V. Zhizhin, A.G. Rybkin, “Effects of induced spin-orbit coupling in formation of quantum sp- and d- resonances in low-dimension systems” // Proceedings of the XVII International symposium “Nanophysics and Nanoelectronics”, p. 253, Nizhniy Novgorod, Russia, 2013.
3) I.I. Klimovskikh., M.V. Rusinova, A.A. Rybkina, A.G. Rybkin, E.V. Zhizhin, A.M. Shikin “Spin polarization of interface states in thin films of Bi on Ag/W(110)”, Book of Abstracts, Proceedings "Science and progress" p. 48, St. Petersburg State University, 2013.
4) I.I. Klimovskikh., M.V. Rusinova, A.A. Rybkina, A.G. Rybkin, E.V. Zhizhin, A.M. Shikin “Spin polarization of quantum well and interface states in 2ML Bi/1ML Ag/W(110)”, Proceedings of the XVII International symposium “Nanophysics and Nanoelectronics”, p.226, Nizhniy Novgorod, Russia, 2013.
5) A.M. Shikin, A.A. Rybkina, M.V. Rusinova, I.I. Klimovskikh, A.G. Rybkin, E.V. Zhizhin, E.V. Chulkov and E.E. Krasovskii “Effect of spin–orbit coupling on atomic-like and delocalized quantum well states in Au overlayers on W(110) and Mo(110)”, New Journal of Physics, 15 (2013) 125014.
6) I.I. Klimovskikh, M. V. Rusinova, A. G. Rybkin, A. A. Rybkina, E. V. Zhizhin, and A. M. Shikin “Spin Polarization of QuantumWell and Interface States of Ultrathin Films of Bi on W(110) with Ag Interlayers”,  Bulletin of the RAS 7 (2014) 39.
7) A.M. Shikin, I. Klimovskikh, S.V. Eremeev, A.A. Rybkina, M. Rusinova, A.G. Rybkin, E. Zhizhin, A.Varykhalov, I.P. Rusinov, E.V. Chulkov, K.A. Kokh, V.A. Golyashov and O.E.Tereshchenko, “Electronic and spin structure of the topological insulator Bi2Te2.4Se0.6”, Physical Review B 89 (2014) 12.
8) M.V. Rusinova, I.I. Klimovskikh, A.A. Rybkina, S.E. Eremeev, A.G. Rybkin, E.V. Zhizhin, A.E. Petukhov, I.P. Rusinov, O.E. Tereshchenko and A.M. Shikin, “Electronic and spin structure of topological insulator Bi2Te2.4Se0.6”, Proceedings of the XVIII International symposium “Nanophysics and Nanoelectronics”, p. 226, Nizhniy Novgorod, Russia, 2014.
9) I.I. Klimovskikh, S.S. Tsirkin, A.G. Rybkin, A.A. Rybkina, M.V. Filianina, E.V. Zhizhin, E.V. Chulkov, A.M. Shikin, “Non-trivial spin structure of graphene on Pt(111) at the Fermi level due to spin-dependent hybridization”, Physical Review B 90  (2014) 235431.
10) M.V. Filianina, I.I. Klimovskikh, A.G. Rybkin, V.A. Golyashov, A.E. Petukhov, S.E. Eremeev, I.P. Rusinov, E.V. Chulkov, O.E. Tereshchenko, K.A. Kokh and A.M. Shikin, “Electronic, spin and atomic structure of topological insulators under contact with noble metals”, Proceedings of the XIX International symposium “Nanophysics and Nanoelectronics”, p. 304, Nizhniy Novgorod, Russia, 2015.