Superconducting Order Parameters in Spin Space Groups: Methodology and Application

TL;DR

This paper develops a systematic method for constructing superconducting order parameters based on spin space groups, enabling detailed analysis of superconducting states and their interaction with magnetic orders.

Contribution

It introduces a novel framework for describing superconducting gap functions in spin space groups, expanding the understanding beyond magnetic space groups.

Findings

Constructed basis functions for superconducting order parameters.

Analyzed possible superconducting ground states.

Discussed interplay between superconductivity and magnetic orders.

Abstract

We employ a systematic approach to construct superconducting order parameters based on the spin space group. Compared to magnetic space groups where spatial and spin rotation of elements are completely locked, the superconducting channels and the forms of basis functions in spin space groups can be different. Furthermore, we utilize the obtained basis functions to construct the Ginzburg-Landau free energy and discuss the possible superconducting ground states as well as the interplay between superconducting states and magnetic orders. By virtue of those results, we discuss the application of our theory to realistic systems. Our work provides a rigorous description of superconducting gap functions in the case of spin space group, and enables further study of the interplay between superconductivity and magnetism.