Fluctuations and topological transitions of quantum Hall stripes: nematics as anisotropic hexatics

TL;DR

This paper investigates the fluctuations and topological phase transitions of quantum Hall stripe states, proposing that the quantum Hall nematic can be viewed as an anisotropic hexatic, with a calculated transition temperature and a phase diagram.

Contribution

It introduces the concept of the quantum Hall nematic as an anisotropic hexatic and explicitly calculates the transition temperature from the anisotropic Wigner crystal to the nematic phase.

Findings

Identification of the quantum Hall nematic as an anisotropic hexatic.

Explicit calculation of the transition temperature.

Proposal of a phase diagram for the 2D electron gas near half-filling.

Abstract

We study fluctuations and topological melting transitions of quantum Hall stripes near half-filling of intermediate Landau levels. Taking the stripe state to be an anisotropic Wigner crystal (AWC) allows us to identify the quantum Hall nematic state conjectured in previous studies of the 2D electron gas as an {\em anisotropic hexatic}. The transition temperature from the AWC to the quantum Hall nematic state is explicitly calculated, and a tentative phase diagram for the 2D electron gas near half-filling is suggested.