title: Ideal two-dimensional electron systems with a giant Rashba-type spin splitting in real materials: surfaces of bismuth tellurohalides.
abstract: Spintronics is aimed at actively controlling and manipulating the spin degrees of freedom in semiconductor devices. A promising way to achieve this goal is to make use of the tunable Rashba effect that relies on the spin-orbit interaction in a two-dimensional electron system immersed in an inversion-asymmetric environment. The spin-orbit-induced spin splitting of the two-dimensional electron state provides a basis for many theoretically proposed spintronic devices. However, the lack of semiconductors with large Rashba effect hinders realization of these devices in actual practice. Here we report on a giant Rashba-type spin splitting in two-dimensional electron systems that reside at tellurium-terminated surfaces of bismuth tellurohalides. Among these semiconductors, BiTeCl stands out for its isotropic metallic surface-state band with the Γ-point energy lying deep inside the bulk band gap. The giant spin splitting of this band ensures a substantial spin asymmetry of the inelastic mean free path of quasiparticles with different spin orientations.
authors.affiliation: Institute of Strength Physics and Materials Science, 634021, Tomsk, Russia.
authors.forename: S V
authors.initials: SV
authors.lastname: Eremeev
authors.forename: I A
authors.initials: IA
authors.lastname: Nechaev
authors.forename: Yu M
authors.initials: YM
authors.lastname: Koroteev
authors.forename: P M
authors.initials: PM
authors.lastname: Echenique
authors.forename: E V
authors.initials: EV
authors.lastname: Chulkov