Dyakonov-Perel-like Orbital and Spin Relaxations in Centrosymmetric Systems

TL;DR

This paper reveals that Dyakonov-Perel-like mechanisms govern orbital and spin relaxation in centrosymmetric systems, challenging previous beliefs and showing anisotropic behavior influenced by electron wavefunctions.

Contribution

It demonstrates DP-like orbital relaxation in centrosymmetric systems and its impact on spin relaxation, extending the understanding of relaxation mechanisms beyond non-centrosymmetric materials.

Findings

Orbital relaxation exhibits DP-like behavior in centrosymmetric systems.

DP-like orbital relaxation influences spin relaxation via spin-orbit coupling.

Relaxations are anisotropic even in high-symmetry materials.

Abstract

The Dyakonov-Perel (DP) mechanism of spin relaxation has long been considered irrelevant in centrosymmetric systems since it was developed originally for non-centrosymmetric ones. We investigate whether this conventional understanding extends to the realm of orbital relaxation, which has recently attracted significant attention. Surprisingly, we find that orbital relaxation in centrosymmetric systems exhibits the DP-like behavior in the weak scattering regime. Moreover, the DP-like orbital relaxation can make the spin relaxation in centrosymmetric systems DP-like through the spin-orbit coupling. We also find that the DP-like orbital and spin relaxations are anisotropic even in materials with high crystal symmetry (such as face-centered cubic structure) and may depend on the orbital and spin nature of electron wavefunctions.