Topological invariants for the Fermi surface of a time-reversal-invariant superconductor

Xiao Liang Qi, Taylor L. Hughes, Shou Cheng Zhang

Research output: Contribution to journalArticlepeer-review

Abstract

A time-reversal-invariant (TRI) topological superconductor has a full pairing gap in the bulk and topologically protected gapless states on the surface or at the edge. In this paper, we show that in the weak pairing limit, the topological quantum number of a TRI superconductor can be completely determined by the Fermi-surface properties and is independent of the electronic structure away from the Fermi surface. In three dimensions, the integer topological quantum number in a TRI superconductor is determined by the sign of the pairing order parameter and the first Chern number of the Berry phase gauge field on the Fermi surfaces. In two dimensions and one dimension, the Z2 topological quantum number of a TRI superconductor is determined simply by the sign of the pairing order parameter on the Fermi surfaces. Our results could directly aid the search for topological superconductors in real materials.

Original languageEnglish (US)
Article number134508
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume81
Issue number13
DOIs
StatePublished - Apr 5 2010
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Topological invariants for the Fermi surface of a time-reversal-invariant superconductor'. Together they form a unique fingerprint.

Cite this