title: Topological Crystalline Insulator in a New Bi Semiconducting Phase.
abstract: 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 nM = -2, but not a 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.
authors.affiliation: Departamento de Física, Facultad de Ciencias, Universidad de Chile &Centro para el Desarrollo de la Nanociencia y la Nanotecnologia, CEDENNA, Santiago, Chile.
authors.forename: F
authors.initials: F
authors.lastname: Munoz
authors.affiliation: Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain.
authors.forename: M G
authors.initials: MG
authors.lastname: Vergniory
authors.affiliation: Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Rauch
authors.affiliation: Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Henk
authors.affiliation: Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain.|Tomsk State University, Tomsk, Russia.|Departamento de Fisica de materiales, Facultad de Ciencias Quimicas, UPV/EHU and Centro de Fisica de Materiales, Centro Mixto CSIC-UPV/EHU, San Sebastian, Spain.|St. Petersburg State University, St. Petersburg, Russia.
authors.forename: E V
authors.initials: EV
authors.lastname: Chulkov
authors.affiliation: Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.|Max Planck Institute of Microstructure Physics, Halle, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Mertig
authors.affiliation: Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität Jena, Jena, Germany.|Institut Lumière Matière (UMR5306), Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne Cedex, France.
authors.forename: S
authors.initials: S
authors.lastname: Botti
authors.affiliation: Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.|Institut Lumière Matière (UMR5306), Université Lyon 1-CNRS, Université de Lyon, F-69622 Villeurbanne Cedex, France.
authors.forename: M A L
authors.initials: MA
authors.lastname: Marques
authors.affiliation: Physics Department, West Virginia University, Morgantown, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Romero