Eberly College of Arts and Sciences
Physics and Astronomy
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 Z2 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
Digital Commons Citation
Munoz, F.; Vergniory, M. G.; Rauch, T.; Henk, J.; Chulkov, E. V.; Mertig, I.; Botti, S.; Marques, M. A. L.; and Romero, A. H., "Topological Crystalline Insulator In A New Bi Semiconducting Phase" (2016). Faculty & Staff Scholarship. 2259.
Munoz, F., Vergniory, M. G., Rauch, T., Henk, J., Chulkov, E. V., Mertig, I., … Romero, A. H. (2016). Topological Crystalline Insulator in a New Bi Semiconducting Phase. Scientific Reports, 6(1). https://doi.org/10.1038/srep21790