Surface versus bulk state in topological insulator Bi2Se3 under environmental disorder

Abstract

Topological insulators (TIs) are predicted to be composed of an insulating bulk state along with conducting channels on the boundary of the material. In Bi2Se3, however, the Fermi level naturally resides in the conduction band due to intrinsic doping by selenium vacancies, leading to metallic bulk states. In such non-ideal TIs it is not well understood how the surface and bulk states behave under environmental disorder. In this letter, based on transport measurements of Bi2Se3 thin films, we show that the bulk states are sensitive to environmental disorder but the surface states remain robust.

13 pages, 3 figures, 1 table, Error in Figure 2(c) corrected and replaced

References in corpus (4)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Topological origin of subgap conductance in insulating bilayer graphene
• Coexistence of the topological state and a two-dimensional electron gas on the surface of Bi2Se3
• Surface State Transport and Ambipolar Electric Field Effect in Bi2Se3 Nanodevices