Superconductivity and local non-centrosymmetricity in crystal lattices

TL;DR

This paper explores how local non-centrosymmetricity in crystal lattices influences superconductivity, extending the understanding of pairing mechanisms in materials lacking global inversion symmetry.

Contribution

It introduces an extended classification of Cooper-pairing channels considering local inversion symmetry breaking within crystal lattices.

Findings

Analysis of three crystal structures with local non-centrosymmetricity

Identification of potential relevance to iron-pnictide superconductors

Extension of superconductivity classification based on lattice symmetry

Abstract

Symmetry of the crystal lattice can be a determining factor for the structure of Cooper pairs in unconventional superconductors. In this study we extend the discussion of superconductivity in non-centrosymmetric materials to the case when inversion symmetry is missing locally, but is present on a global level. Concretely, we investigate the staggered non-centrosymmetricity within a regular sublattice structure, in some analogy to the discussion of superconductivity in antiferromagnetic systems. Three crystal structures are analyzed in detail as illustrative examples for the extended classification of Cooper-pairing channels. One of the cases may be relevant for the class of iron-pnictide superconductors.