Exploring Quantum Hall Physics at Ultra-Low Temperatures and at High Pressures

TL;DR

This paper reviews advanced experimental techniques involving ultra-low temperatures and high pressures to explore complex quantum Hall phenomena, revealing new states, phase transitions, and transport behaviors in two-dimensional electron systems.

Contribution

It introduces novel experimental approaches and presents new findings on fractional quantum Hall states and phase transitions at extreme conditions.

Findings

Discovery of new odd denominator fractional quantum Hall states

Observation of phase transitions in half-filled Landau levels

Enhanced understanding of reentrant integer quantum Hall states

Abstract

The use of ultra-low temperature cooling and of high hydrostatic pressure techniques has significantly expanded our understanding of the two-dimensional electron gas confined to GaAs/AlGaAs structures. This chapter reviews a selected set of experiments employing these specialized techniques in the study of the fractional quantum Hall states and of the charged ordered phases, such as the reentrant integer quantum Hall states and the quantum Hall nematic. Topics discussed include a successful cooling technique used, novel odd denominator fractional quantum Hall states, new transport results on even denominator fractional quantum Hall states and on reentrant integer quantum Hall states, and phase transitions observed in half-filled Landau levels.