Finite-frequency response of Rasba electron gas with two-particle scattering

TL;DR

This paper investigates how electron-electron interactions in clean Rashba spin-orbit coupled systems influence their finite-frequency electrical response, revealing a reduction in Drude weight and finite dissipation beyond the Drude peak.

Contribution

It provides a detailed calculation of the finite-frequency response in Rashba systems, highlighting the impact of electron-electron scattering on conductivity features.

Findings

Electron-electron scattering reduces the Drude weight.

Finite dissipative response appears outside the Drude peak.

Effects are prominent in clean Rashba conductors.

Abstract

Two-dimensional systems with Rashba spin-orbit coupling are not Galilean invariant and therefore electron--electron collisions in them may affect the current. However when taken alone, they cannot ensure a nonzero dc resistivity, so their effects are masked by impurity scattering. Here we calculate the related finite-frequency response and show that the electron--electron scattering in clean Rashba conductors decreases the Drude weight while resulting in a finite dissipative component of the response outside of the Drude peak.