Nematic phase of the two-dimensional electron gas in a magnetic field

TL;DR

This paper develops an order parameter theory for the nematic phase in a 2D electron gas under magnetic fields, explaining transport anomalies and proposing experiments to measure critical behavior.

Contribution

It introduces a theoretical framework for the electron nematic phase in 2DEG, combining scaling and Monte Carlo methods, and predicts finite-temperature transition behavior.

Findings

Resistivity anisotropy behaves like an order parameter.

Transition occurs at approximately 65 mK.

Small background anisotropy rounds the transition.

Abstract

The two dimensional electron gas (2DEG) in moderate magnetic fields in ultra-clean AlAs-GaAs heterojunctions exhibits transport anomalies suggestive of a compressible, anisotropic metallic state. Using scaling arguments and Monte Carlo simulations, we develop an order parameter theory of an electron nematic phase. The observed temperature dependence of the resistivity anisotropy behaves like the orientational order parameter if the transition to the nematic state occurs at a finite temperature, $T_c \sim 65 mK$, and is slightly rounded by a small background microscopic anisotropy. We propose a light scattering experiment to measure the critical susceptibility.