Spin dynamics of hopping electrons in quantum wires: algebraic decay and noise

TL;DR

This paper presents a theoretical study of spin decoherence and noise in semiconductor quantum wires, revealing algebraic decay and power-law features caused by electron hopping and hyperfine interactions.

Contribution

It introduces an analytical model and simulations that describe disorder-dependent algebraic spin decay and noise spectra in quantum wires with localized electrons.

Findings

Algebraic tails in spin decay due to disorder

Power-law singularities in low-frequency spin noise

Hopping dynamics significantly influence spin coherence

Abstract

We study theoretically spin decoherence and intrinsic spin noise in semiconductor quantum wires caused by an interplay of electron hopping between the localized states and the hyperfine interaction of electron and nuclear spins. At a sufficiently low density of localization sites the hopping rates have an exponentially broad distribution. It allows the description of the spin dynamics in terms of closely-situated "pairs" of sites and single "reaching" states, from which the series of hops result in the electron localized inside a "pair". The developed analytical model and numerical simulations demonstrate disorder-dependent algebraic tails in the spin decay and power-law singularity-like features in the low-frequency part of the spin noise spectrum.