Circuit with small-capacitance high-quality Nb Josephson junctions

Abstract

We have developed a fabrication process for nanoscale tunnel junctions which includes focused-ion-beam etching from different directions. By applying the process to a Nb/(Al-)Al_2O_3/Nb trilayer, we have fabricated a Nb single-electron transistor (SET), and characterized the SET at low temperatures, T=0.04-40 K. The superconducting gap energy and the transition temperature of the Nb SET agree with the bulk values, which suggests high quality Nb junctions. The single-electron charging energy of the SET is estimated to be larger than 1 K.

Published version, RevTeX4

References in corpus (6)

• Quantum state engineering with Josephson-junction devices
• Coherent control of macroscopic quantum states in a single-Cooper-pair box
• Coherent Quantum Dynamics of a Superconducting Flux Qubit
• Fabrication of mesoscopic Nb wires using conventional e-beam lithographic techniques
• Multilayer technique developed for fabricating Nb-based single-electron devices
• Single electron transistors with high quality superconducting niobium islands

Cited by in corpus (5)

• Single-charge devices with ultrasmall Nb/AlOx/Nb trilayer Josephson junctions
• Parity effect in Al and Nb single electron transistors in a tunable environment
• Periodicity in Al/Ti superconducting single electron transistors
• Anodization-free fabrication process for high-quality cross-type Josephson tunnel junctions based on a Nb/Al-AlO${}_x$/Nb trilayer
• Method for finding the critical temperature of the island in a SET structure