title: Emergence of non-centrosymmetric topological insulating phase in BiTeI under pressure.
abstract: The spin-orbit interaction affects the electronic structure of solids in various ways. Topological insulators are one example in which the spin-orbit interaction leads the bulk bands to have a non-trivial topology, observable as gapless surface or edge states. Another example is the Rashba effect, which lifts the electron-spin degeneracy as a consequence of the spin-orbit interaction under broken inversion symmetry. It is of particular importance to know how these two effects, that is, the non-trivial topology of electronic states and the Rashba spin splitting, interplay with each other. Here we show through sophisticated first-principles calculations that BiTeI, a giant bulk Rashba semiconductor, turns into a topological insulator under a reasonable pressure. This material is shown to exhibit several unique features, such as a highly pressure-tunable giant Rashba spin splitting, an unusual pressure-induced quantum phase transition, and more importantly, the formation of strikingly different Dirac surface states at opposite sides of the material.
authors.affiliation: Correlated Electron Research Group (CERG), RIKEN-ASI, Wako, Saitama 351-0198, Japan. bahramy@riken.jp
authors.forename: M S
authors.initials: MS
authors.lastname: Bahramy
authors.forename: B-J
authors.initials: BJ
authors.lastname: Yang
authors.forename: R
authors.initials: R
authors.lastname: Arita
authors.forename: N
authors.initials: N
authors.lastname: Nagaosa
mesh_terms: D002627:Chemistry, Physical / Q000379:methods; D003460:Crystallization; D004581:Electronics; D004583:Electrons; D004867:Equipment Design; D007700:Kinetics; D008422:Materials Testing; D008968:Molecular Conformation; D011312:Pressure; D012666:Semiconductors