Spin susceptibilities, spin densities and their connection to spin-currents

TL;DR

This paper investigates the frequency-dependent spin susceptibilities in a 2D electron gas with Rashba and Dresselhaus interactions, revealing how their resonances depend on tunable parameters and connecting spin densities to spin currents.

Contribution

It provides exact continuity equations linking spin density and spin current, and analyzes how susceptibilities influence spin dynamics in the presence of spin-orbit interactions.

Findings

Resonance frequencies depend on Rashba and Dresselhaus constants.

Spin susceptibilities are central to spin dynamics in the model.

Spin density and current are proportional to susceptibilities.

Abstract

We calculate the frequency dependent spin susceptibilities for a two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit interaction. The resonances of the susceptibilities depends on the relative values of the Rashba and Dresselhaus spin-orbit constants, which could be manipulated by gate voltages. We derive exact continuity equations, with source terms, for the spin density and use those to connect the spin current to the spin density. In the free electron model the susceptibilities play a central role in the spin dynamics since both the spin density and the spin current are proportional to them.