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MM: Fachverband Metall- und Materialphysik
MM 43: Frontiers of Electronic-Structure Theory: Focus on Topology and Transport
MM 43.4: Poster
Wednesday, March 9, 2016, 18:15–20:30, Poster A
Electric switchable giant Rashba-type spin splitting in bulk PbS — •Bin Shao1, Wenhui Duan2, and Thomas Frauenheim1 — 1BCCMS, University of Bremen, Bremen, Germany — 2Institute for Advanced Study, Tsinghua University, Beijing, China
Realizing electric controllable spin is one of the major challenges in the field of spintronics. A promising approach is to utilize so-called Rashba effect, which arises from the spin-orbit coupling under broken inversion symmetry, leading to a momentum-dependent spin splitting in k-space. However, the sizes of this splitting are usually rather small, which hinders the application of this effect in spintronics. In this work, based on density functional calculation, we predict a giant Rashba-type spin splitting in bulk PbS with space group P63mc. The phonon spectrum calculation gives evidence of the thermal stability of this system. The origin of the giant Rashba effect has been demonstrated from the deviation of the S ion from the inversion symmetric position, leading to an ferroelectric polarization along c axis. By switching the direction of the ferroelectric polarization, the spin directions of bulk carriers governed by the Rashba effect are completely rotated, which grants a potential approach to manipulate the spin of electrons by an external electric field. Moreover, under a reasonable hydrostatic pressure, the system could obtain the inversion symmetry due to the movement of the S ion backwards to symmetric positions. As a result, the system turns into a topological phase with the massless Dirac cone state at the (001) surface.