Gap closing and universal phase diagrams in topological insulators

Shuichi Murakami

doi:10.1016/j.physe.2010.07.043

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arXiv · 1006.1188

Gap closing and universal phase diagrams in topological insulators

Shuichi Murakami

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Abstract

We study a general problem how the gap in a nonmagnetic band insulator closes by tuning a parameter. We review our recent results on the classification of all the possible gap closing in two and three dimensions. We show that they accompany the change of Z_2 topological numbers, and that the gap closings correspond to phase transitions between the quantum spin Hall and the insulator phases. Interestingly, in inversion-asymmetric three-dimensional systems there appears a gapless phase between the quantum spin Hall and insulator phases. This gapless phase is due to a topological nature of gap-closing points in three dimensions, but not in two dimensions.

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Shuichi Murakami. 2010-08-15. Gap closing and universal phase diagrams in topological insulators. https://doi.org/10.1016/j.physe.2010.07.043

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