Magnetic-Field Induced Semimetal in Topological Crystalline Insulator Thin Films

Abstract

We investigate electromagnetic properties of a topological crystalline insulator (TCI) thin film under external electromagnetic fields. The TCI thin film is a topological insulator indexed by the mirror-Chern number. It is demonstrated that the gap closes together with the emergence of a pair of gapless cones carrying opposite chirarities by applying in-plane magnetic field. A pair of gapless points have opposite vortex numbers. This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. We thus present an a magnetic-field induced semimetal-semiconductor transition in 2D material. This is a giant-magnetoresistance, where resistivity is controlled by magnetic field. Perpendicular electric field is found to shift the gapless points and also renormalize the Fermi velocity in the direction of the in-plane magnetic field.

4 pages, 4 figures

References in corpus (7)

• Topological Crystalline Insulators
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• Dirac materials
• Topological response in Weyl semimetals and the chiral anomaly
• Surface States of the Topological Insulator Bi_{1-x}Sb_x
• Compact Skyrmions, Merons and Bimerons in Thin Chiral Magnetic Films
• Electron Correlation Induced Spontaneous Symmetry Breaking and Weyl Semimetal Phase in a Strongly Spin-Orbit Coupled System