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arXiv · 1103.1430

Weak topological insulator with protected gapless helical states

Ken-Ichiro Imura·Yositake Takane·Akihiro Tanaka
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Abstract

A workable model for describing dislocation lines introduced into a three-dimensional topological insulator is proposed. We show how fragile surface Dirac cones of a weak topological insulator evolve into protected gapless helical modes confined to the vicinity of dislocation line. It is demonstrated that surface Dirac cones of a topological insulator (either strong or weak) acquire a finite-size energy gap, when the surface is deformed into a cylinder penetrating the otherwise surface-less system. We show that when a dislocation with a non-trivial Burgers vector is introduced, the finite-size energy gap play the role of stabilizing the one-dimensional gapless states.

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Ken-Ichiro Imura, Yositake Takane, Akihiro Tanaka. 2011-06-23. Weak topological insulator with protected gapless helical states. https://doi.org/10.1103/physrevb.84.035443

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