Unconventional dc transport in Rashba electron gases

TL;DR

This paper investigates the transport behavior of disordered Rashba electron gases, revealing a transition from standard Drude behavior at high densities to spin-orbit sensitive conductivity at lower densities, highlighting the complex interplay of spin and charge.

Contribution

It provides a detailed analysis of dc transport regimes in Rashba electron gases, identifying conditions where Drude's law applies and where it breaks down due to spin-orbit effects.

Findings

Drude law holds at high densities with strong Rashba coupling.

Breakdown of Drude behavior occurs at low densities with dominant spin-orbit effects.

dc conductivity becomes highly sensitive to spin-orbit strength in the low-density regime.

Abstract

We discuss the transport properties of a disordered two-dimensional electron gas with strong Rashba spin-orbit coupling. We show that in the high-density regime where the Fermi energy overcomes the energy associated with spin-orbit coupling, dc transport is accurately described by a standard Drude's law, due to a non-trivial compensation between the suppression of back-scattering and the relativistic correction to the quasi-particle velocity. On the contrary, when the system enters the opposite dominant spin-orbit regime, Drude's paradigm breaks down and the dc conductivity becomes strongly sensitive to the spin-orbit coupling strength, providing a suitable tool to test the entanglement between spin and charge degrees of freedom in these