Carbon Nanotube Quantum Dots with Nb Contacts

TL;DR

This paper demonstrates the fabrication of carbon nanotube quantum dots with niobium superconducting contacts, showing gate-tunable supercurrents and hysteretic IV characteristics, enhanced by an on-chip resistive environment.

Contribution

It introduces a method to create carbon nanotube quantum dots with superconducting niobium contacts and investigates their supercurrent and switching behavior.

Findings

Gate-controllable supercurrents up to 30 nA

Hysteretic IV-curves at low temperature

Switching histograms with widths of 0.5-2

Abstract

We report on the preparation of carbon nanotube quantum dots using superconducting electrodes made of niobium. Gate-controllable supercurrents with values of up to 30 nA are induced by the proximity effect. The IV-curves are hysteretic at low temperature and the corresponding switching histograms have a width of ~0.5-2. An on-chip resistive environment integrated in the sample layout is used in order to increase the switching current.