Wave Function Mismatches and Coulomb Drag

TL;DR

This paper investigates how wave function mismatches in double layer systems at filling factor 1/2 affect topological excitations and Coulomb drag, revealing infinite sensitivity of the Chern number and damping of Goldstone modes.

Contribution

It introduces the impact of wave function mismatches on topological properties and drag resistance in disordered double layer quantum Hall systems.

Findings

Chern number sensitivity to impurities is infinite due to wave function mismatches.

Goldstone mode damping is significant at low temperatures.

Unique temperature dependence of drag resistance is predicted.

Abstract

In this paper, I study the topological excitations in a pairing state in double layer systems at Landau level filling factor $\nu=1/2$ in the presence of disorders. Due to mismatches between single particle wave functions of composite Fermions in different layers, the sensitivity of the Chern number of the pairing state, with respect to changes of impurities, is infinity. Consequently, Goldstone mode in this pairing state is strongly damped at low temperature. It is argued that this leads to a unique temperature dependence of the drag resistance at low temperature.