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arXiv · 1304.4569

The effect of interactions on 2D fermionic symmetry-protected topological phases with Z2 symmetry

Zheng-Cheng Gu·Michael Levin
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Abstract

We study the effect of interactions on 2D fermionic symmetry-protected topological (SPT) phases using the recently proposed braiding statistics approach. We focus on a simple class of examples: superconductors with a Z2 Ising symmetry. Although these systems are classified by Z in the noninteracting limit, our results suggest that the classification collapses to Z8 in the presence of interactions -- consistent with previous work that analyzed the stability of the edge. Specifically, we show that there are at least 8 different types of Ising superconductors that cannot be adiabatically connected to one another, even in the presence of strong interactions. In addition, we prove that each of the 7 nontrivial superconductors have protected edge modes.

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Zheng-Cheng Gu, Michael Levin. 2013-04-16. The effect of interactions on 2D fermionic symmetry-protected topological phases with Z2 symmetry. https://doi.org/10.1103/physrevb.89.201113

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