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arXiv · 1406.1009

Magnetic-Field Induced Semimetal in Topological Crystalline Insulator Thin Films

Motohiko Ezawa
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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.

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Motohiko Ezawa. 2014-10-29. Magnetic-Field Induced Semimetal in Topological Crystalline Insulator Thin Films. https://doi.org/10.1016/j.physleta.2015.02.028

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