Multiple Andreev Reflections in a Carbon Nanotube Quantum Dot

TL;DR

This paper investigates multiple Andreev reflections in a carbon nanotube quantum dot with superconducting contacts, showing how the subharmonic gap features depend on quantum dot energy levels and comparing experimental results with theoretical models.

Contribution

It presents the first detailed experimental observation and theoretical analysis of resonant multiple Andreev reflections in a carbon nanotube quantum dot system.

Findings

Subharmonic gap structures depend on quantum dot energy levels.

Experimental data aligns with the theoretical model.

Resonant Andreev reflections are observed in the device.

Abstract

We report resonant multiple Andreev relections in a multiwall carbon nanotube quantum dot coupled to superconducting leads. The position and magnitude of the subharmonic gap structure is found to depend strongly on the level positions of the single-electron states which are adjusted with a gate electrode. We discuss a theoretical model of the device and compare the calculated differential conductance with the experimental data. (pdf including figures, see: www.unibas.ch/phys-meso/Research/Papers/2003/MAR-MWNT.pdf)