Correlated tunneling and the instability of the fractional quantum Hall edge

TL;DR

This paper investigates how correlated tunneling interactions between composite fermions can destabilize the traditional edge theory of fractional quantum Hall systems, revealing the potential for edge reconstruction.

Contribution

It introduces a class of interaction terms previously neglected in the standard theory and demonstrates their role in causing edge instabilities and reconstructions.

Findings

Correlated tunneling can destabilize the fractional quantum Hall edge.

Traditional edge theory is incomplete without considering these interactions.

Edge reconstruction may lead to additional conducting channels.

Abstract

We consider a class of interaction terms that describes correlated tunneling of composite fermions between effective Landau levels. Despite being generic and of similar strength to that of the usual density-density couplings, these terms are not included in the accepted theory of the edges of fractional quantum Hall systems. Here we show that they may lead to an instability of the edge towards a new reconstructed state with additional channels, and thereby demonstrate the incompleteness of the traditional edge theory.