Unconventional spin textures emerging from a universal symmetry theory of spin-momentum locking

TL;DR

This paper introduces a universal symmetry-based theory to classify and predict diverse spin textures in materials, revealing new types and their dependence on atomic orbitals and sites, with implications for spintronic applications.

Contribution

It provides a comprehensive symmetry framework for understanding and predicting novel spin textures, including previously unreported types, in various materials.

Findings

Predicted Zeeman-type spin splitting in antiferromagnets

Identified quadratic spin textures in certain materials

Validated predictions with first-principles calculations

Abstract

Spin textures, i.e., the distribution of spin polarization vectors in reciprocal space, exhibit diverse patterns determined by symmetry constraints, resulting in a variety of spintronic phenomena. Here, we propose a universal theory to comprehensively describe the nature of spin textures by incorporating three symmetry flavors of reciprocal wavevector, atomic orbital and atomic site. Such approach enables us to establish a complete classification of spin textures constrained by the little co-group and predict unprecedentedly reported spin texture types, such as Zeeman-type spin splitting in antiferromagnets and quadratic spin texture. To illustrate the influence of atomic orbitals and sites on spin textures, we predict orbital-dependent spin texture and anisotropic spin-momentum-site locking effects, and corresponding material candidates validated through first-principles calculations. The comprehensive classification and the predicted new spin textures in realistic materials are expected to trigger future spin-based functionalities in electronics.