Reentrant anisotropic phases in a two-dimensional hole system

TL;DR

This paper reports the discovery of reentrant anisotropic phases in a 2D hole system under magnetic fields, highlighting differences from electron systems due to strong spin-orbit coupling, with implications for understanding quantum Hall states.

Contribution

It reveals reentrant anisotropic phases in a 2D hole system and attributes these differences from electron systems to strong spin-orbit coupling effects.

Findings

Anisotropic charge transport at nu=7/2 and nu=11/2 below 150mK

Isotropic transport at nu=9/2 for all temperatures

Differences from electron systems attributed to spin-orbit coupling

Abstract

Anisotropic charge transport is observed in a two-dimensional (2D) hole system in a perpendicular magnetic field at filling factors nu=7/2 and nu=11/2 for temperatures below 150mK. In stark contrast, the transport at nu=9/2 is isotropic for all temperatures. Our results for a two-dimensional hole system differ substantially from 2D electron transport where no anisotropy has been observed at nu=7/2, the strongest anisotropy occurs at nu=9/2, and reentrant behavior is not evident. We attribute this difference to strong spin-orbit coupling in the hole system.