Fractional Shot Noise in the Kondo Regime

TL;DR

This paper demonstrates that shot noise measurements in the Kondo regime reveal a universal fractional charge of 5/3 e, highlighting many-body effects in low-temperature quantum dot transport.

Contribution

It shows that inelastic processes in the Kondo regime lead to a universal fractional shot noise value, providing new insights into many-body phenomena in Fermi-liquid systems.

Findings

Shot noise is enhanced to a fractional value of 5/3 e.

The fractional charge indicates many-body effects in the Kondo regime.

Symmetry breaking perturbations influence the shot noise behavior.

Abstract

Low temperature transport through a quantum dot in the Kondo regime proceeds by a universal combination of elastic and inelastic processes, as dictated by the low-energy Fermi-liquid fixed point. We show that as a result of inelastic processes, the charge detected by a shot-noise experiment is enhanced relative to the noninteracting situation to a universal fractional value, $e^*=5/3 e$. Thus, shot noise reveals that the Kondo effect involves many-body features even at low energies, despite its Fermi-liquid nature. We discuss the influence of symmetry breaking perturbations.