Fractionalization noise in edge channels of integer quantum Hall states

TL;DR

This paper theoretically analyzes current noise caused by charge fractionalization in edge channels of integer quantum Hall states, revealing how capacitive coupling and plasma modes generate measurable fluctuations without net current.

Contribution

It provides analytical expressions for fractionalization-induced noise in quantum Hall edge channels, including asymptotic behaviors at different bias regimes.

Findings

Fractional charges propagate as plasma modes due to capacitive coupling.

Charge fractionalization induces low-frequency current noise without net current.

Analytical formulas describe noise dependence on bias voltage.

Abstract

A theoretical calculation is presented of current noise which is due charge fractionalization, in two interacting edge channels in the integer quantum Hall state at filling factor $\nu=2$. Because of the capacitive coupling between the channels, a tunneling event, in which an electron is transferred from a biased source lead to one of the two channels, generates propagating plasma mode excitations which carry fractional charges on the other edge channel. When these excitations impinge on a quantum point contact, they induce low-frequency current fluctuations with no net average current. A perturbative treatment in the weak tunneling regime yields analytical integral expressions for the noise as a function of the bias on the source. Asymptotic expressions of the noise in the limits of high and low bias are found.