Thin films of a three-dimensional topological insulator in a strong magnetic field: a microscopic study

Abstract

The response of thin films of Bi${}_2$Se${}_3$ to a strong perpendicular magnetic field is investigated by performing magnetic bandstructure calculations for a realistic multi-band tight-binding model. Several crucial features of Landau quantization in a realistic three-dimensional topological insulator are revealed. The $n=0$ Landau level is absent in ultra-thin films, in agreement with experiment. In films with a crossover thickness of five quintuple layers, there is a signature of the $n=0$ level, whose overall trend as a function of magnetic field matches the established low-energy effective-model result. Importantly, we find a field-dependent splitting and a strong spin-polarization of the $n=0$ level which can be measured experimentally at reasonable field strengths. Our calculations show mixing between the surface and bulk Landau levels which causes the character of levels to evolve with magnetic field.

5 pages, 4 figures

References in corpus (4)

• Topological origin of subgap conductance in insulating bilayer graphene
• Two-dimensional Dirac fermions in a topological insulator: transport in the quantum limit
• Momentum-Resolved Landau-Level Spectroscopy of Dirac Surface State in Bi2Se3
• Electronic Structures and Surface States of Topological Insulator Bi${}_{1-x}$Sb${}_x$

Cited by in corpus (2)

• Confined electron states in two-dimensional HgTe in magnetic field: Quantum-dot versus quantum-ring behavior
• Unconventional quantum Hall effect in Floquet topological insulators