Articulo
Topological Crystalline Insulator in a New Bi Semiconducting Phase
SCIENTIFIC REPORTS
Registro en:
1150806
1150806
Autor
Muñoz-Saez, Francisco Javier
Vergniory, M G
Rauch, T
Henk, J
Chulkov, E V
Mertig, I
Botti, S
Marques, M A L
Romero, A H
Institución
Resumen
Topological crystalline insulators are a type of topological insulators whose topological surface states are protected by a crystal symmetry, thus the surface gap can be tuned by applying strain or an electric field. In this paper we predict by means of ab initio calculations a new phase of Bi which is a topological crystalline insulator characterized by a mirror Chern number n(M) = -2, but not a Z(2) strong topological insulator. This system presents an exceptional property: at the (001) surface its Dirac cones are pinned at the surface high-symmetry points. As a consequence they are also protected by time-reversal symmetry and can survive against weak disorder even if in-plane mirror symmetry is broken at the surface. Taking advantage of this dual protection, we present a strategy to tune the band-gap based on a topological phase transition unique to this system. Since the spin-texture of these topological surface states reduces the back-scattering in carrier transport, this effective band-engineering is expected to be suitable for electronic and optoelectronic devices with reduced dissipation. Regular 2015 FONDECYT FONDECYT