Surface-interface anomalies and topological order in Bi2Se3
Department of Condensed Matter Physics and Materials' Science, Tata Institute of Fundamental Research Homi Bhabha Road, Colaba, Mumbai-400005, India
Received: 13 March 2015
Accepted: 30 March 2015
We studied the layer-resolved electronic structure of a typical topological insulator, Bi2Se3, employing the density functional theory and discovered that the Dirac states primarily consist of the states at the interface of surface and sub-surface quintuple layers in the pristine material instead of the major surface character expected for such systems. The emergence of these states depends strongly on the surface terminations. The surface character of the Dirac states becomes most prominent on the oxygen-deposited Bi-terminated surface due to the change in covalency by the relatively more electronegative oxygen atoms.
PACS: 73.20.At – Surface states, band structure, electron density of states / 03.65.Vf – Phases: geometric; dynamic or topological / 68.43.-h – Chemisorption/physisorption: adsorbates on surfaces
© EPLA, 2015