Band inversion at critical magnetic fields in a silicene quantum dot

¹ Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada - Fuentenueva s/n, 18071 Granada, Spain
² Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada - 18071 Granada, Spain
³ Departamento de Matemática Aplicada, Universidad de Granada - Fuentenueva s/n, 18071 Granada, Spain

^(a) eromera@ugr.es
^(b) calixto@ugr.es

Received: 24 June 2015
Accepted: 27 July 2015

Abstract

We have found out that the band inversion in a silicene quantum dot (QD), in perpendicular magnetic B and electric fields, drastically depends on the strength of the magnetic field. We study the energy spectrum of the silicene QD where the electric field provides a tunable band gap Δ. Boundary conditions introduce chirality, so that negative and positive angular-momentum m zero Landau level (ZLL) edge states show a quite different behavior regarding the band-inversion mechanism underlying the topological insulator transition. We show that, whereas some ZLLs suffer band inversion at for any B > 0, other ZLLs only suffer band inversion above critical values of the magnetic field at nonzero values of the gap.