Possible observation of phase coexistence of the $\nu=1/3$ fractional quantum Hall liquid and a solid

TL;DR

This study reports the observation of phase coexistence between a fractional quantum Hall liquid and a solid in a high-quality two-dimensional hole system, indicated by unusual oscillations in magnetoresistance near the $ u=1/3$ filling.

Contribution

The paper provides experimental evidence for a possible coexistence of fractional quantum Hall liquid and solid phases, suggesting a new intermediate electronic phase.

Findings

Observation of oscillatory magnetoresistance near $ u=1/3$

Identification of a potential phase transition region

Evidence for coexistence of quantum Hall liquid and solid phases

Abstract

We have measured the magnetoresistance of a very low density and an extremely high quality two-dimensional hole system. With increasing magnetic field applied perpendicularly to the sample we observe the sequence of insulating, $\nu=1/3$ fractional quantum Hall liquid, and insulating phases. In both of the insulating phases in the vicinity of the $\nu=1/3$ filling the magnetoresistance has an unexpected oscillatory behavior with the magnetic field. These oscillations are not of the Shubnikov-de Haas type and cannot be explained by spin effects. They are most likely the consequence of the formation of a new electronic phase which is intermediate between the correlated Hall liquid and a disorder pinned solid.