Universality at integer quantum Hall transitions

TL;DR

This paper investigates the universal properties of integer quantum Hall transitions through experimental, theoretical, and numerical studies, demonstrating the universality of conductivity tensor and Thouless conductance at these critical points.

Contribution

It provides new evidence that both conductivity tensor and Thouless conductance are universal at integer quantum Hall transitions, supported by experiments, theory, and simulations.

Findings

Conductivity tensor is universal at transitions

Thouless conductance is universal at integer quantum Hall transitions

Finite temperature and size effects are characterized near the transition

Abstract

We report in this paper results of experimental and theoretical studies of transitions between different integer quantum Hall phases, as well as transition between the insulating phase and quantum Hall phases at high magnetic fields. We focus mainly on universal properties of the transitions. We demonstrate that properly defined conductivity tensor is universal at the transitions. We also present numerical results of a non-interacting electron model, which suggest that the Thouless conductance is universal at integer quantum Hall transitions, just like the conductivity tensor. Finite temperature and system size effects near the transition point are also studied.