A Quantum Dot in the Kondo Regime Coupled to Superconductors

TL;DR

This paper investigates the interplay between the Kondo effect and superconductivity in a carbon nanotube quantum dot system, revealing that Kondo correlations persist when the Kondo temperature exceeds the superconducting gap.

Contribution

It provides experimental evidence of the conditions under which Kondo correlations survive in the presence of superconductivity in quantum dots.

Findings

Kondo correlations persist when Kondo temperature exceeds the superconducting gap

Superconductivity does not destroy Kondo effects under certain conditions

Transport measurements reveal the delicate interplay between Kondo and superconducting phenomena

Abstract

The Kondo effect and superconductivity are both prime examples of many-body phenomena. Here we report transport measurements on a carbon nanotube quantum dot coupled to superconducting leads that show a delicate interplay between both effects. We demonstrate that the superconductivity of the leads does not destroy the Kondo correlations on the quantum dot when the Kondo temperature, which varies for different single-electron states, exceeds the superconducting gap energy.