The inequality of charge and spin diffusion coefficients

TL;DR

This paper demonstrates analytically that charge and spin diffusion coefficients can differ significantly in quantum wires, challenging the common assumption that they are equal in drift-diffusion models of spin transport.

Contribution

It reveals the potential disparity between charge and spin diffusion coefficients in quantum wires, emphasizing the need to distinguish them in transport modeling.

Findings

Charge and spin diffusion coefficients can differ vastly in quantum wires.

Common assumptions of equality in diffusion coefficients may not hold in low-dimensional systems.

Highlighting the importance of accurate modeling for quantum wire devices.

Abstract

Since spin and charge are both carried by electrons (or holes) in a solid, it is natural to assume that charge and spin diffusion coefficients will be the same. Drift-diffusion models of spin transport typically assume so. Here, we show analytically that the two diffusion coefficients can be vastly different in quantum wires. Although we do not consider quantum wells or bulk systems, it is likely that the two coefficients will be different in those systems as well. Thus, it is important to distinguish between them in transport models, particularly those applied to quantum wire based devices