Quantum Dot coupled to a normal and a superconducting lead

TL;DR

This study investigates how a carbon nanotube quantum dot's conductance behavior varies when coupled to normal and superconducting leads, revealing the influence of Kondo temperature and superconducting gap on zero bias resonance.

Contribution

It provides experimental insights into the interplay between Kondo effect and superconductivity in quantum dots, supported by comparison with a resonant level-superconductor interface model.

Findings

Zero bias conductance resonance splits or persists depending on $T_K/Δ$ ratio.

Experimental data aligns with a simple resonant level-superconductor model.

Highlights the role of Kondo temperature in quantum dot-superconductor systems.

Abstract

We report on electrical transport measurements in a carbon nanotube quantum dot coupled to a normal and a superconducting lead. Depending on the ratio of Kondo temperature $T_{K}$ and superconducting gap $\Delta$ the zero bias conductance resonance either is split into two side-peaks or persists. We also compare our data with a simple model of a resonant level - superconductor interface.