On the low-field insulator-quantum Hall conductor transitions

TL;DR

This paper investigates the transition from insulator to quantum Hall conductor in a 2D GaAs system with InAs quantum dots, highlighting a broad crossover from localization to Landau quantization.

Contribution

It provides new insights into the wide magnetic field range over which the insulator-quantum Hall transition occurs, emphasizing the crossover nature.

Findings

Transition involves a broad crossover from localization to Landau quantization.

The insulator-quantum Hall transition is not confined to a narrow critical region.

The study uses a gated 2D GaAs system with embedded InAs quantum dots.

Abstract

We studied the insulator-quantum Hall conductor transition which separates the low-field insulator from the quantum Hall state of the filling factor $\nu=4$ on a gated two-dimensional GaAs electron system containing self-assembled InAs quantum dots. To enter the $\nu=4$ quantum Hall state directly from the low-field insulator, the two-dimensional system undergoes a crossover from the low-field localization to Landau quantization. The crossover, in fact, covers a wide range with respect to the magnetic field rather than only a small region near the critical point of the insulator-quantum Hall conductor transition.