Measuring the Kondo effect in the Aharonov-Bohm interferometer

TL;DR

This paper presents a method to extract the quantum dot Green function from conductance oscillations in an Aharonov-Bohm interferometer, revealing how magnetic flux influences the Kondo effect and phase shifts.

Contribution

It provides a novel approach to determine the dot Green function from experimental conductance data, accounting for flux and device parameters affecting the Kondo physics.

Findings

The conductance oscillations encode the quantum dot Green function.

Phase shift $eta$ varies with device parameters and can deviate from $rac{ ext{pi}}{2}$.

Parameters can suppress the Kondo temperature, affecting Kondo behavior.

Abstract

The conductance ${\cal G}$ of an Aharonov-Bohm interferometer (ABI), with a strongly correlated quantum dot on one arm, is expressed in terms of the dot Green function, $G_{dd}$, the magnetic flux $\phi$ and the non-interacting parameters of the ABI. We show that one can extract $G_{dd}$ from the observed oscillations of ${\cal G}$ with $\phi$, for both closed and open ABI's. In the latter case, the phase shift $\beta$ deduced from ${\cal G} \approx A+B\cos(\phi+\beta)$ depends strongly on the ABI's parameters, and usually $\beta \ne \pi/2$. These parameters may also reduce the Kondo temperature, eliminating the Kondo behavior.