Charge Fractionalization in a Kondo Device

TL;DR

This paper investigates charge fractionalization in a charge Kondo device near the two-channel Kondo critical point, revealing universal fractional charge transport signatures through current and shot noise measurements.

Contribution

It provides the first detailed analysis of nonequilibrium transport and shot noise in a charge Kondo device, identifying fractional charge carriers as a hallmark of non-Fermi liquid behavior.

Findings

Universal Fano factor of 1/2 indicating fractional charge

Elementary transport involves weak scattering of emergent fermions with half-integer charge

Fractionalization signatures observable at higher temperatures compared to spin-Kondo devices

Abstract

We study nonequilibrium transport through a charge Kondo device realizing the two-channel Kondo critical point in a recent experiment by Iftikhar et al. By computing the current and shot noise at low voltages near the critical point, we obtain a universal Fano factor $e^*/e=1/2$. We identify elementary transport processes as weak scattering of emergent fermions carrying half-integer charge quantum numbers. This forms an experimental fingerprint for fractionalization in a non-Fermi liquid, which, compared to spin-Kondo devices, could be observed at elevated temperatures.