Quantum states and linear response in dc and electromagnetic fields for charge current and spin polarization of electrons at Bi/Si interface with giant spin-orbit coupling

摘要

An expansion of the nearly free-electron model constructed by Frantzeskakis,Pons and Grioni [Phys. Rev. B {\bf 82}, 085440 (2010)] describing quantumstates at Bi/Si(111) interface with giant spin-orbit coupling is developed andapplied for the band structure and spin polarization calculation, as well asfor the linear response analysis for charge current and induced spin caused bydc field and by electromagnetic radiation. It is found that the largespin-orbit coupling in this system may allow resolving the spin-dependentproperties even at room temperature and at realistic collision rate. Thegeometry of the atomic lattice combined with spin-orbit coupling leads to ananisotropic response both for current and spin components related to theorientation of the external field. The in-plane dc electric field produces onlythe in-plane components of spin in the sample while both the in-plane andout-of-plane spin components can be excited by normally propagatingelectromagnetic wave with different polarizations.