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arXiv · 0907.3224

Translation invariant topological superconductors on lattice

Su-Peng Kou·Xiao-Gang Wen
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Abstract

In this paper we introduce four Z_2 topological indices zeta_k=0,1 at k=(0,0), (0,pi), (pi, 0), (pi, pi) characterizing 16 universal classes of 2D superconducting states that have translation symmetry but may break any other symmetries. The 16 classes of superconducting states are distinguished by their even/odd numbers of fermions on even-by-even, even-by-odd, odd-by-even, and odd-by-odd lattices. As a result, the 16 classes topological superconducting states exist even for interacting systems. For non-interacting systems, we find that zeta_k is the number of electrons on k=(0,0), (0,pi), (pi, 0), or (pi,pi) orbitals (mod 2) in the ground state. For 3D superconducting states with only translation symmetry, there are 256 different types of topological superconductors.

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Su-Peng Kou, Xiao-Gang Wen. 2009-07-21. Translation invariant topological superconductors on lattice. https://doi.org/10.1103/physrevb.82.144501

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