Edge reconstruction in the $\nu=2/3$ fractional quantum Hall state

TL;DR

This paper develops a theory of edge reconstruction in the $ u=2/3$ fractional quantum Hall state, explaining recent experimental phenomena such as upstream neutral modes, conductance plateaus, and charge crossover through a renormalization group analysis.

Contribution

The paper introduces a new edge reconstruction model incorporating an additional $ u=1/3$ incompressible strip, providing a unified explanation for various experimental observations.

Findings

Explains upstream neutral modes and conductance plateaus.

Accounts for temperature-dependent effective charge crossover.

Provides a renormalization group framework for disorder and interactions.

Abstract

The edge structure of the $\nu=2/3$ fractional quantum Hall state has been studied for several decades but recent experiments, exhibiting upstream neutral mode(s), a plateau at a Hall conductance of $\frac{1}{3}( e^2/h)$ through a quantum point contact, and a crossover of the effective charge, from $e/3$ at high temperature to $2e/3$ at low temperature, could not be explained by a single theory. Here we develop such a theory, based on edge reconstruction due to a confining potential with finite slope, that admits an additional $\nu=1/3$ incompressible strip near the edge. Renormalization group analysis of the effective edge theory due to disorder and interactions explains the experimental observations.