Two-electron bunching in transport through a QD induced by Kondo correlations

TL;DR

This paper investigates noise in a quantum dot exhibiting Kondo correlations, revealing two-electron bunching effects near the unitary limit, with backscattered charge exceeding the elementary charge, confirming theoretical predictions.

Contribution

The study provides experimental evidence of two-electron backscattering in a quantum dot with Kondo correlations, extending previous theoretical predictions.

Findings

Backscattered charge of approximately 5e/3 near the unitary limit.

Two-electron backscattering dominates over single-electron processes.

Results hold up to half the Kondo temperature.

Abstract

We report on noise measurements in a quantum dot in the presence of Kondo correlations. Close to the unitary limit, with the conductance reaching 1.8e2/h, we observed an average backscattered charge of e*~5e/3, while weakly biasing the quantum dot. This result held to bias voltages up to half the Kondo temperature. Away from the unitary limit, the charge was measured to be e as expected. These results confirm and extend the prediction by E. Sela et al. [1], that suggested that two-electron backscattering processes dominate over single-electron backscattering processes near the unitary limit, with an average backscattered charge e*~5e/3.