Glide-Plane Symmetry and Superconducting Gap Structure of Iron-Based Superconductors

TL;DR

This paper explores how glide-plane symmetry influences pairing mechanisms and superconducting gap structures in iron-based superconductors, revealing that certain exotic pairing states are inevitable but do not alter observable gap features.

Contribution

It demonstrates the inevitability of $ ext{eta}$-pairing in the presence of specific orbital symmetries and clarifies that observable gap functions match earlier models despite exotic pairing possibilities.

Findings

$ ext{eta}$-pairing is inevitable with certain orbital symmetries

Observable gap functions are consistent with earlier models

Exotic pairing states do not alter measurable gap structures

Abstract

We consider the effect of glide-plane symmetry of the Fe-pnictogen/chalcogen layer in Fe-based superconductors on pairing in spin fluctuation models. Recent theories have proposed that so-called $\eta$-pairing states with nonzero total momentum can be realized and possess exotic properties such as odd parity spin singlet symmetry and time-reversal symmetry breaking. Here we show that $\eta$ pairing is inevitable when there is orbital weight at the Fermi level from orbitals with even and odd mirror reflection symmetry in $z$; however, by explicit calculation, we conclude that the gap function that appears in observable quantities is identical to that found in earlier, 1 Fe per unit cell pseudocrystal momentum calculations.