This article is cited in 16 papers

CONDENSED MATTER

Interface induced states at the boundary between a $3D$ topological insulator and a normal insulator

V. N. Men'shov^a, V. V. Tugushev^a, E. V. Chulkov<sup>bc

a</sup> National Research Centre "Kurchatov Institute"
^b Tomsk State University
^c Departamento de Física de Materiales, Facultad de Quimica, UPV/EHU, San Sebastian, Basque Country

Abstract: We show that, when a three-dimensional ($3D$) narrow-gap semiconductor with inverted band gap (“topological insulator”, TI) is attached to a $3D$ wide-gap semiconductor with non-inverted band gap (“normal insulator”, NI), two types of bound electron states having different spatial distributions and spin textures arise at the TI/NI interface. Namely, the gapless (“topological”) bound state can be accompanied by the emergence of the gapped (“ordinary”) bound state. We describe these states in the framework of the envelope function method using a variational approach for the energy functional; their existence hinges on the ambivalent character of the constraint for the envelope functions that correspond to the “open” or “natural” boundary conditions at the interface. The properties of the ordinary state strongly depend on the effective interface potential, while the topological state is insensitive to the interface potential variation.

Received: 29.01.2013

Language: English

DOI: 10.7868/S0370274X13050044

 English version: Journal of Experimental and Theoretical Physics Letters, 2013, 97:5, 258–264

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