Electrostatic effects and band bending in doped topological insulators

We investigate the electrostatic effects in doped topological insulators by developing a self-consistent scheme for an interacting tight-binding model. The presence of bulk carriers, in addition to surface electrons, generates an intrinsic inhomogeneous charge density in the vicinity of the surface...

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Main Authors: Galanakis, Dimitrios., Stanescu, Tudor D.
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2013
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Online Access:https://hdl.handle.net/10356/95366
http://hdl.handle.net/10220/9242
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-953662023-02-28T19:34:44Z Electrostatic effects and band bending in doped topological insulators Galanakis, Dimitrios. Stanescu, Tudor D. School of Physical and Mathematical Sciences DRNTU::Science::Physics::Electricity and magnetism We investigate the electrostatic effects in doped topological insulators by developing a self-consistent scheme for an interacting tight-binding model. The presence of bulk carriers, in addition to surface electrons, generates an intrinsic inhomogeneous charge density in the vicinity of the surface and, as a result, band-bending effects are present. We find that electron doping and hole doping produce band-bending effects of similar magnitude and opposite signs. The presence of additional surface dopants breaks this approximate electron-hole symmetry and dramatically affects the magnitude of the band bending. Application of a gate potential can generate a depletion zone characterized by a vanishing carrier density. We find that the density profile in the transition zone between the depleted region and the bulk is independent of the applied potential. In thin films the electrostatic effects are strongly dependent on the carrier charge density. In addition, we find that substrate-induced potentials can generate a Rashba-type spin-orbit coupling in ultrathin topological insulator films. We calculate the profiles of bulk and surface states in topological insulator films and identify the conditions corresponding to both types of state being localized within the same region in space. Published version 2013-02-25T04:55:21Z 2019-12-06T19:13:34Z 2013-02-25T04:55:21Z 2019-12-06T19:13:34Z 2012 2012 Journal Article Galanakis, D., & Stanescu, T. D. (2012). Electrostatic effects and band bending in doped topological insulators. Physical review B, 86(19), 195311-. https://hdl.handle.net/10356/95366 http://hdl.handle.net/10220/9242 10.1103/PhysRevB.86.195311 en Physical review B © 2012 American Physical Society. This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society. The paper can be found at the following official DOI: [10.1103/PhysRevB.86.195311]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Science::Physics::Electricity and magnetism
spellingShingle DRNTU::Science::Physics::Electricity and magnetism
Galanakis, Dimitrios.
Stanescu, Tudor D.
Electrostatic effects and band bending in doped topological insulators
description We investigate the electrostatic effects in doped topological insulators by developing a self-consistent scheme for an interacting tight-binding model. The presence of bulk carriers, in addition to surface electrons, generates an intrinsic inhomogeneous charge density in the vicinity of the surface and, as a result, band-bending effects are present. We find that electron doping and hole doping produce band-bending effects of similar magnitude and opposite signs. The presence of additional surface dopants breaks this approximate electron-hole symmetry and dramatically affects the magnitude of the band bending. Application of a gate potential can generate a depletion zone characterized by a vanishing carrier density. We find that the density profile in the transition zone between the depleted region and the bulk is independent of the applied potential. In thin films the electrostatic effects are strongly dependent on the carrier charge density. In addition, we find that substrate-induced potentials can generate a Rashba-type spin-orbit coupling in ultrathin topological insulator films. We calculate the profiles of bulk and surface states in topological insulator films and identify the conditions corresponding to both types of state being localized within the same region in space.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Galanakis, Dimitrios.
Stanescu, Tudor D.
format Article
author Galanakis, Dimitrios.
Stanescu, Tudor D.
author_sort Galanakis, Dimitrios.
title Electrostatic effects and band bending in doped topological insulators
title_short Electrostatic effects and band bending in doped topological insulators
title_full Electrostatic effects and band bending in doped topological insulators
title_fullStr Electrostatic effects and band bending in doped topological insulators
title_full_unstemmed Electrostatic effects and band bending in doped topological insulators
title_sort electrostatic effects and band bending in doped topological insulators
publishDate 2013
url https://hdl.handle.net/10356/95366
http://hdl.handle.net/10220/9242
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