Slow spin relaxation in a quantum Hall ferromagnet state

TL;DR

This paper investigates electron spin relaxation in a quantum Hall ferromagnet, revealing significantly longer relaxation times and identifying a specific relaxation mechanism involving spin-exciton annihilation influenced by spin-orbit coupling and disorder.

Contribution

It reports the observation of unusually long spin relaxation times in a quantum Hall ferromagnet and clarifies the underlying relaxation mechanism.

Findings

Spin relaxation times are at least ten times longer than previous measurements.

Relaxation time shows no dependence on electron temperature or spin-exciton density.

Relaxation is mediated by spin-exciton annihilation via spin-orbit coupling and smooth disorder.

Abstract

Electron spin relaxation in a spin-polarized quantum Hall state is studied. Long spin relaxation times that are at least an order of magnitude longer than those measured in previous experiments were observed and explained within the spin-exciton relaxation formalism. Absence of any dependence of the spin relaxation time on the electron temperature and on the spin-exciton density, and specific dependence on the magnetic field indicate the definite relaxation mechanism -- spin-exciton annihilation mediated by spin-orbit coupling and smooth random potential.