Absence of Scaling in the Integer Quantum Hall Effect

TL;DR

This study investigates the transition region between quantum Hall states using edge magnetoplasmon measurements, revealing a finite transition width at zero frequency and challenging existing critical phenomena theories.

Contribution

It provides experimental evidence that the transition does not exhibit expected scaling behavior, suggesting a different underlying mechanism.

Findings

Transition width increases linearly with frequency

Transition width remains finite at zero frequency

Data contradicts prevalent critical phenomena theories

Abstract

We have studied the conductivity peak in the transition region between the two lowest integer Quantum Hall states using transmission measurements of edge magnetoplasmons. The width of the transition region is found to increase linearly with frequency but remains finite when extrapolated to zero frequency and temperature. Contrary to prevalent theoretical pictures, our data does not show the scaling characteristics of critical phenomena.These results suggest that a different mechanism governs the transition in our experiment.