Unexpected tunneling current from downstream neutral modes

TL;DR

This paper investigates how downstream neutral modes influence transport and noise in fractional quantum Hall states, revealing that average current is affected by downstream perturbations, which can be observed experimentally.

Contribution

It demonstrates that downstream neutral modes impact both noise and average transmitted current, providing new insights into edge state transport in fractional quantum Hall systems.

Findings

Downstream perturbations affect average transmitted current.

Noise measurements can reveal downstream mode effects.

Theoretical predictions align with experimental observations.

Abstract

We analyze transport through a quantum point contact in fractional quantum Hall states with counter-propagating neutral edge modes. We show that both the noise (as expected and previously calculated by other authors) and (perhaps surprisingly) the average transmitted current are affected by downstream perturbations within the standard edge state model. We consider two different scenarios for downstream perturbations. We argue that the change in transmitted current should be observable in experiments that have observed increased noise.