Spin-orbit coupling and semiclassical electron dynamics in noncentrosymmetric metals

TL;DR

This paper analyzes how spin-orbit coupling influences electron dynamics in noncentrosymmetric metals, highlighting the role of Berry curvature and topological effects on observable quantum phenomena like the de Haas-van Alphen effect.

Contribution

It provides a symmetry-based framework for understanding spin-orbit effects and semiclassical electron motion, incorporating Berry curvature and topological band features in noncentrosymmetric metals.

Findings

Derived semiclassical equations including Berry curvature effects.

Identified topological sources of Berry curvature at band degeneracies.

Discussed modifications to quantum oscillation phenomena due to wavefunction topology.

Abstract

Spin-orbit coupling of electrons with the crystal lattice plays a crucial role in materials without inversion symmetry, lifting spin degeneracy of the Bloch states and endowing the resulting nondegenerate bands with complex spin textures and topologically nontrivial wavefunctions. We present a detailed symmetry-based analysis of the spin-orbit coupling and the band degeneracies in noncentrosymmetric metals. We systematically derive the semiclassical equations of motion for fermionic quasiparticles near the Fermi surface, taking into account both the spin-orbit coupling and the Zeeman interaction with an applied magnetic field. Some of the lowest-order quantum corrections to the equations of motions can be expressed in terms of a fictitious "magnetic field" in the momentum space, which is related to the Berry curvature of the band wavefunctions. The band degeneracy points or lines serve as sources of a topologically nontrivial Berry curvature. We discuss the observable effects of the wavefunction topology, focusing, in particular, on the modifications to the Lifshitz-Onsager semiclassical quantization condition and the de Haas-van Alphen effect in noncentrosymmetric metals.