Anomalous Transmission Phase of a Kondo-Correlated Quantum Dot

TL;DR

This paper investigates the phase behavior of electron transmission through a Kondo-correlated quantum dot, explaining large phase shifts observed experimentally and proposing this as a universal feature of the high-temperature Kondo regime.

Contribution

It introduces a model combining nonresonant transmission with the Anderson impurity to explain anomalous phase evolution in Kondo systems.

Findings

Large phase shifts (~π) observed in experiments are explained by the model.

Anomalous phase evolution is shown to be a universal property of the high-temperature Kondo phase.

The model accounts for the effects of time-reversal symmetry on phase behavior.

Abstract

We study phase evolution of transmission through a quantum dot with Kondo correlations. By considering a model that includes nonresonant transmission as well as the Anderson impurity, we explain unusually large phase evolution of about $\pi$ in the Kondo valley observed in recent experiments. We argue that this anomalous phase evolution is a universal property that can be found in the high-temperature Kondo phase in the presence of the time-reversal symmetry.