Chirality, charge and spin-density wave instabilities of a two-dimensional electron gas in the presence of Rashba spin-orbit coupling

TL;DR

This paper demonstrates that a two-dimensional electron gas with Rashba spin-orbit coupling exhibits a universal instability of the homogeneous paramagnetic state towards spin-density-wave and charge-density-wave distortions, extending Overhauser's theorem.

Contribution

It generalizes Overhauser's Hartree-Fock instability theorem to include Rashba spin-orbit coupling in 2D electron gases, analyzing the properties of resulting inhomogeneous states.

Findings

Homogeneous paramagnetic state is unstable for all densities.

Instability leads to spin-density-wave and charge-density-wave states.

Inhomogeneous states have distinct properties analyzed in the study.

Abstract

We show that a result equivalent to Overhauser's famous Hartree-Fock instability theorem can be established for the case of a two-dimensional electron gas in the presence of Rashba spin-obit coupling. In this case it is the spatially homogeneous paramagnetic chiral ground state that is shown to be differentially unstable with respect to a certain class of distortions of the spin-density-wave and charge-density-wave type. The result holds for all densities. Basic properties of these inhomogeneous states are analyzed.