Transition from a fractional quantum Hall liquid to an electron solid at Landau level filling nu = 1/3 in tilted magnetic fields

TL;DR

This study observes a transition from a fractional quantum Hall liquid to a Wigner solid in a high-quality 2D hole system as the magnetic field is tilted, indicating a strong coupling effect under these conditions.

Contribution

It provides experimental evidence of a phase transition from FQHE liquid to Wigner solid in a 2D hole system under tilted magnetic fields, highlighting the role of Landau level coupling.

Findings

FQHE state weakens with tilt angle increase

Magnetoresistivity rises significantly at high tilt angles

Transition attributed to Landau level coupling effects

Abstract

We have observed in a low density two-dimensional hole system (2DHS) of extremely high quality (with hole density p=1.6x10^{10} cm^{-2} and mobility \mu=0.8x10^6 cm^2/Vs) that, as the 2DHS is continuously tilted with respect to the direction of the magnetic field, the \nu=1/3 fractional quantum Hall effect (FQHE) state is weakened and its magnetoresistivity rises from ~ 0.4 kohm/square in the normal orientation to ~ 180 kohm/square at tilt angle \theta \~ 80 degrees. We attribute this phenomenon to the transition of the 2DHS from the FQHE liquid state to the pinned Wigner solid state, and argue that its origin is the strong coupling of subband Landau levels under the tilted magnetic fields.