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arXiv · 0708.1639

Many-body generalization of the Z2 topological invariant for the quantum spin Hall effect

Sung-Sik Lee·Shinsei Ryu
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Abstract

We propose a many-body generalization of the Z2 topological invariant for the quantum spin Hall insulator, which does not rely on single-particle band structures. The invariant is derived as a topological obstruction that distinguishes topologically distinct many-body ground states on a torus. It is also expressed as a Wilson-loop of the SU(2) Berry gauge field, which is quantized due to the time-reversal symmetry.

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Sung-Sik Lee, Shinsei Ryu. 2008-05-02. Many-body generalization of the Z2 topological invariant for the quantum spin Hall effect. https://doi.org/10.1103/physrevlett.100.186807

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