Spin precession and alternating spin polarization in spin-3/2 hole systems

TL;DR

This paper explores how spin-3/2 hole systems exhibit intrinsic spin precession and alternating spin polarization due to spin-orbit coupling, with implications for spin relaxation and potential device applications.

Contribution

It demonstrates that hole spin polarization and higher-order multipoles can precess without external magnetic fields, expanding understanding of spin dynamics in hole systems.

Findings

Hole spin precession occurs due to spin-orbit coupling.

Alternating spin polarization can be experimentally observed.

Precession influences spin relaxation processes.

Abstract

The spin density matrix for spin-3/2 hole systems can be decomposed into a sequence of multipoles which has important higher-order contributions beyond the ones known for electron systems [R. Winkler, Phys. Rev. B \textbf{70}, 125301 (2004)]. We show here that the hole spin polarization and the higher-order multipoles can precess due to the spin-orbit coupling in the valence band, yet in the absence of external or effective magnetic fields. Hole spin precession is important in the context of spin relaxation and offers the possibility of new device applications. We discuss this precession in the context of recent experiments and suggest a related experimental setup in which hole spin precession gives rise to an alternating spin polarization.