Z_{2}-enriched symmetry indicators for topological superconductors in the 1651 magnetic space groups

While the symmetry-based diagnosis of topological insulators and semimetals has enabled large-scale discovery of topological materials candidates, the extension of these approaches to the diagnosis of topological superconductors remains a major open question. One important new ingredient in the anal...

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Bibliographic Details
Main Authors: Seishiro Ono, Hoi Chun Po, Ken Shiozaki
Format: Article
Language:English
Published: American Physical Society 2021-05-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.3.023086
Description
Summary:While the symmetry-based diagnosis of topological insulators and semimetals has enabled large-scale discovery of topological materials candidates, the extension of these approaches to the diagnosis of topological superconductors remains a major open question. One important new ingredient in the analysis of topological superconductivity is the presence of Z_{2}-valued Pfaffian invariants associated with certain high-symmetry momenta. Such topological invariants lie beyond the conventional scope of symmetry representation theory for band structures, and as such they are nontrivial to incorporate into the systematic calculations of the symmetry indicators of band topology. Here, we overcome this challenge and report the full computation of the Z_{2}-enriched symmetry indicators for superconductors in all symmetry settings. Our results indicate that incorporating the Z_{2} band labels enhance the diagnostic power of the scheme in roughly 60% of the symmetry settings. Our framework can also be readily integrated with first-principles calculations to elucidate on the possible properties of unconventional superconductivity in a given compound. As a demonstration, we analyze explicitly the interplay between pairing symmetry and topological superconductivity in the recently discovered superconductors CaPtAs and CaSb_{2}.
ISSN:2643-1564