Near-Perfect Correlation of the Resistance Components of Mesoscopic Samples at the Quantum Hall Regime

TL;DR

This study reveals near-perfect correlations between resistance fluctuations in mesoscopic samples at the quantum Hall transition, challenging existing models and affecting the interpretation of transition widths.

Contribution

It provides new experimental evidence of correlated resistance fluctuations and discusses implications for edge-state transport models in the quantum Hall regime.

Findings

Near-perfect correlation between longitudinal and Hall resistance fluctuations.

Correlated fluctuations occur where two-terminal resistance is quantized.

Results introduce ambiguity in measuring quantum Hall transition widths.

Abstract

We study the four-terminal resistance fluctuations of mesoscopic samples near the transition between the $\nu=2$ and the $\nu=1$ quantum Hall states. We observe near-perfect correlations between the fluctuations of the longitudinal and Hall components of the resistance. These correlated fluctuations appear in a magnetic-field range for which the two-terminal resistance of the samples is quantized. We discuss these findings in light of edge-state transport models of the quantum Hall effect. We also show that our results lead to an ambiguity in the determination of the width of quantum Hall transitions.