Interactions suppress Quasiparticle Tunneling at Hall Bar Constrictions

TL;DR

This paper investigates how electron-electron interactions near constrictions in fractional quantum Hall systems suppress quasiparticle tunneling, contrasting with previous expectations of enhancement at low temperatures.

Contribution

It reveals that interactions near the constriction can suppress tunneling, providing a new understanding of quasiparticle behavior in fractional quantum Hall systems.

Findings

Interactions suppress quasiparticle tunneling at constrictions.

Experimental observations differ from traditional theoretical predictions.

Electron-electron interactions are crucial near quantum point contacts.

Abstract

Tunneling of fractionally charged quasiparticles across a two-dimensional electron system on a fractional quantum Hall plateau is expected to be strongly enhanced at low temperatures. This theoretical prediction is at odds with recent experimental studies of samples with weakly-pinched quantum-point-contact constrictions, in which the opposite behavior is observed. We argue here that this unexpected finding is a consequence of electron-electron interactions near the point contact.