Kondo resonance enhanced supercurrent in single wall carbon nanotube Josephson junctions

TL;DR

This paper investigates how Kondo resonances influence supercurrent in single wall carbon nanotube Josephson junctions, revealing enhanced supercurrent due to Kondo effects and multiple Andreev reflections.

Contribution

It demonstrates the interplay between Kondo resonances and superconductivity in nanotube junctions, highlighting the enhancement of supercurrent via Kondo effects.

Findings

Kondo regime exhibits a four-fold shell structure

Superconducting signatures observed below critical temperature

Proximity-induced supercurrent linked to Kondo resonances

Abstract

We have contacted single wall carbon nanotubes grown by chemical vapor deposition to superconducting Ti/Al/Ti electrodes. The device, we here report on is in the Kondo regime exhibiting a four-fold shell structure, where a clear signature of the superconducting electrodes is observed below the critical temperature. Multiple Andreev reflections are revealed by sub-gap structure and a narrow peak in the differential conductance around zero bias is seen depending on the shell filling. We interpret the peak as a proximity induced supercurrent and examine its interplay with Kondo resonances.