Abstract

The energy band of a topological insulator is calculated taken into account second and third neighbors. A tight-binding model based on the Bernevig-Hughes-Zhang (BHZ) approach for quantum wells is used to calculate the energies. The BHZ model is characterized by the mass term M(q) = Delta - Bq(2). In the microscopic theory used here, the mass term is E-(q) = Delta - B(sin(2) q(x)a/2 + sin(2) q(y)a/2). That is modified when second and/or third neighbors are included in the model. As a consequence, depending on the parameters used the range where the material is an insulator is changed. (C) 2017 Elsevier B.V. All rights reserved.

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