From insulator to quantum Hall liquid at low magnetic fields

TL;DR

This study investigates the transition from insulator to quantum Hall liquid in a 2D electron system at low magnetic fields, revealing an intermediate regime with oscillations explained by standard theory.

Contribution

It provides experimental evidence for an intermediate regime between insulator and quantum Hall liquid, characterized by Shubnikov-de Haas oscillations.

Findings

Observation of temperature-independent resistivity points

Identification of an intermediate regime with oscillations

Support for conventional oscillation theory in this regime

Abstract

We have performed low-temperature transport measurements on a GaAs two-dimensional electron system at low magnetic fields. Multiple temperature-independent points and accompanying oscillations are observed in the longitudinal resistivity between the low-field insulator and the quantum Hall (QH) liquid. Our results support the existence of an intermediate regime, where the amplitudes of magneto-oscillations can be well described by conventional Shubnikov-de Haas theory, between the low-field insulator and QH liquid.