Spin Relaxation in a Quantized Hall Regime in Presence of a Disorder

TL;DR

This paper investigates how spatial inhomogeneities affect spin relaxation times in a 2D electron gas within the quantum Hall regime, revealing resonance phenomena and non-exponential relaxation near certain filling factors.

Contribution

It introduces a detailed analysis of spin relaxation influenced by disorder and predicts a magneto-confinement resonance affecting relaxation rates.

Findings

SR times range from 10^{-8} to 10^{-6} seconds.

Resonance enhances SR rate when Zeeman energy matches confinement level spacing.

Non-monotonic B-dependence of SR time near resonance.

Abstract

We study the spin relaxation (SR) of a two-dimensional electron gas (2DEG) in the quantized Hall regime and discuss the role of spatial inhomogeneity effects on the relaxation. The results are obtained for small filling factors ($\nu\ll 1$) or when the filling factor is close to an integer. In either case SR times are essentially determined by a smooth random potential. For small $\nu$ we predict a "magneto-confinement" resonance manifested in the enhancement of the SR rate when the Zeeman energy is close to the spacing of confinement sublevels in the low-energy wing of the disorder-broadened Landau level. In the resonant region the $B$-dependence of the SR time has a peculiar non-monotonic shape. If $\nu\simeq 2n+1$, the SR is going non-exponentially. Under typical conditions the calculated SR times range from $10^{-8}$ to $10^{-6} $s.