Symmetry-imposed shape of linear response tensors

TL;DR

This paper revises and extends a scheme to determine the symmetry-imposed shape of linear response tensors, applying it to spin conductivity tensors across all magnetic space groups and uncovering a new spin transport phenomenon.

Contribution

The paper introduces an extended scheme for analyzing the symmetry constraints on linear response tensors, enabling comprehensive study of spin transport in various magnetic and nonmagnetic materials.

Findings

Applied the scheme to all magnetic space groups for spin conductivity tensors.

Identified conditions for longitudinal and transverse spin transport effects.

Discovered a new longitudinal spin transport phenomenon in certain nonmagnetic solids.

Abstract

A scheme suggested in the literature to determine the symmetry-imposed shape of linear response tensors is revised and extended to allow for the treatment of more complex situations. The extended scheme is applied to discuss the shape of the spin conductivity tensor for all magnetic space groups. This allows in particular investigating the character of longitudinal as well as transverse spin transport for arbitrary crystal structure and magnetic order that give rise e.g.\ to the spin Hall, Nernst and the spin-dependent Seebeck effects. In addition we draw attention to a new longitudinal spin transport phenomenon occurring in certain nonmagnetic solids.