The Quantum Hall Effect in Drag: Inter-layer Friction in Strong Magnetic Fields

TL;DR

This paper investigates Coulomb drag between two electron systems under strong magnetic fields, revealing that drag behavior near quantum Hall transitions reflects critical fluctuations and low-frequency dissipation characteristics.

Contribution

It introduces a novel analysis of Coulomb drag in quantum Hall systems, linking drag behavior to critical fluctuations and dissipation exponents near phase transitions.

Findings

Drag peaks sharply near quantum Hall plateau transitions.

Low temperature drag behavior measures an anomalous dissipation exponent.

Critical fluctuations influence the dissipation and transport properties.

Abstract

We study the Coulomb drag between two spatially separated electron systems in a strong magnetic field, one of which exhibits the quantum Hall effect. At a fixed temperature, the drag mimics the behavior of $\sigma_{xx}$ in the quantum Hall system, in that it is sharply peaked near the transitions between neighboring plateaux. We assess the impact of critical fluctuations near the transitions, and find that the low temperature behavior of the drag measures an exponent $\eta$ that characterizes anomalous low frequency dissipation; the latter is believed to be present following the work of Chalker.