Multipolar spin-orbit coupling in noncentrosymmetric crystals with time-reversal symmetry: Beyond spin
Phys. Rev. B 113, 165137 – Published 20 April, 2026
DOI: https://doi.org/10.1103/2jln-lctf
Abstract
We develop a symmetry-adapted multipolar theory close to the bulk point for time-reversal-symmetric, noncentrosymmetric crystals in the strong atomic spin-orbit-coupling (-coupling) limit. Using a multiplet basis appropriate for heavy-element and bands, we systematically construct all symmetry-allowed spin-orbit-coupling terms up to fifth order in momentum and generalize the usual spin texture to a total-angular-momentum texture. For , multipolar spin-orbit coupling qualitatively reshapes Fermi surfaces and makes the topology of Bloch states band dependent. This leads to anisotropic high- textures that go beyond a single Rashba helix. We classify these textures by their total-angular-momentum vorticity for every energy band and identify distinct phases. We show that their crossovers generate enhanced and nonmonotonic current-induced spin-polarization responses, namely, the Edelstein effect, upon tuning the chemical potential. Our results provide a symmetry-based framework for analyzing and predicting multipolar spin-orbit coupling, total-angular-momentum textures, and spintronic responses in heavy-element materials without an inversion center.
Physics Subject Headings (PhySH)
- Electronic structure
- Rashba coupling
- Spin polarization
- Spin texture
- Spin-orbit coupling
- Spin-orbit torque
- Spintronics
- Symmetries
- Band structure methods
- Boltzmann theory
- Continuous symmetries in condensed matter
- Crystal-field theory
- Discrete symmetries in condensed matter
- Group theory
- Symmetries in condensed matter
- k dot p method