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arXiv · 1407.2484

Spontaneous gap generation on the surface of weakly interacting topological insulators using nonmagnetic impurities

Annica M. Black-Schaffer·Dmitry Yudin
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Abstract

Strong nonmagnetic impurities on the surface of three-dimensional topological insulators (TIs) generate localized resonance peaks close to the Dirac point. We show that this results in a strongly reduced critical Coulomb interaction strength to reach a magnetic surface state, following a Stoner-like criterion. Thus even weakly interacting TIs host a finite (local) magnetization around strong nonmagnetic impurities. The local magnetization gives rise to a global energy gap, linearly dependent on the maximum value of the magnetization but decreasing with reduced impurity concentration.

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Annica M. Black-Schaffer, Dmitry Yudin. 2014-07-09. Spontaneous gap generation on the surface of weakly interacting topological insulators using nonmagnetic impurities. https://doi.org/10.1103/physrevb.90.161413

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