Coulomb drag as a signature of the paired quantum Hall state

TL;DR

This paper investigates Coulomb drag in a two-layer quantum Hall system at filling factor 1/2, revealing a finite drag conductivity in the paired state and its enhancement near the transition temperature, with implications for recent experiments.

Contribution

It demonstrates that Coulomb drag conductivity can be finite in the paired quantum Hall state and explores its temperature dependence, providing new insights into quantum Hall phase transitions.

Findings

Drag conductivity is finite in the paired quantum Hall state at zero temperature.

Drag conductivity is significantly enhanced above the critical temperature.

Results have implications for interpreting recent Coulomb drag experiments.

Abstract

Motivated by the recent Coulomb drag experiment of M. P. Lilly et. al, we study the Coulomb drag in a two-layer system with Landau level filling factor $\nu=1/2$. We find that the drag conductivity in the incompressible paired quantum Hall state at zero temperature can be finite. The drag conductivity is also greatly enhanced above $T_c$, at which the transition between the weakly coupled compressible liquids and the paired quantum Hall liquid takes place. We discuss the implications of our results for the recent experiment.