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Nodal Structure of Superconductors with Time-Reversal Invariance and Z2 Topological Number

Masatoshi Sato
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Abstract

A topological argument is presented for nodal structures of superconducting states with time-reversal invariance. A generic Hamiltonian which describes a quasiparticle in superconducting states with time-reversal invariance is derived, and it is shown that only line nodes are topologically stable in single-band descriptions of superconductivity. Using the time-reversal symmetry, we introduce a real structure and define topological numbers of line nodes. Stability of line nodes is ensured by conservation of the topological numbers. Line nodes in high-Tc materials, the polar state in p-wave paring and mixed singlet-triplet superconducting states are examined in detail.

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Masatoshi Sato. 2006-02-19. Nodal Structure of Superconductors with Time-Reversal Invariance and Z2 Topological Number. https://doi.org/10.1103/physrevb.73.214502

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