Quantization of Topological Invariants under Symmetry-Breaking Disorder

Juntao Song; Emil Prodan

doi:10.1103/physrevb.92.195119

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arXiv · 1507.02605

Quantization of Topological Invariants under Symmetry-Breaking Disorder

Juntao Song·Emil Prodan

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Abstract

In the strictly periodic setting, the electric polarization of inversion-symmetric solids with and without time-reversal symmetry and the isotropic magneto-electric response function of time-reversal symmetric insulators are known to be topological invariants displaying an exact $\mathbb Z_2$ quantization. This quantization is stabilized by the symmetries. In the present work, we investigate the fate of such symmetry-stabilized topological invariants in the presence of a disorder which breaks the symmetries but restores them on average. Using a rigorous analysis, we conclude that the strict quantization still holds in these conditions. Numerical calculations confirm this prediction.

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Juntao Song, Emil Prodan. 2015-11-10. Quantization of Topological Invariants under Symmetry-Breaking Disorder. https://doi.org/10.1103/physrevb.92.195119

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