Strong spin relaxation length dependence on electric field gradients

TL;DR

This paper investigates how inhomogeneous electric field gradients significantly influence spin relaxation lengths, revealing that such effects can drastically suppress electron spin polarization in spin transport systems.

Contribution

It demonstrates the strong dependence of spin relaxation length on electric field gradients using both analytical and numerical methods, highlighting a previously underappreciated factor in spin transport.

Findings

Spin relaxation length varies strongly with electric field gradients.

Significant suppression of spin polarization can occur due to electric field effects.

Spin relaxation length can be comparable to the charge screening length.

Abstract

We discuss the influence of electrical effects on spin transport, and in particular the propagation and relaxation of spin polarized electrons in the presence of inhomogeneous electric fields. We show that the spin relaxation length strongly depends on electric field gradients, and that significant suppression of electron spin polarization can occur as a result thereof. A discussion in terms of a drift-diffusion picture, and self-consistent numerical calculations based on a Boltzmann-Poisson approach shows that the spin relaxation length in fact can be of the order of the charge screening length.