Josephson Junctions defined by a Nano-Plough

TL;DR

This paper presents a novel method for defining superconducting Josephson junctions using a diamond-hard nano-plough created by a modified scanning probe microscope, enabling highly transparent junctions and integrated mesoscopic devices.

Contribution

It introduces a new technique for fabricating superconducting Josephson junctions with high transparency using a nano-plough tool on Aluminum films.

Findings

Successful fabrication of highly transparent Josephson junctions.

Integration of junctions into a dc-SQUID demonstrating proper functionality.

Potential applications as tunable on-chip millimeter wave sources.

Abstract

We define superconducting constrictions by ploughing a deposited Aluminum film with a scanning probe microscope. The microscope tip is modified by electron beam deposition to form a nano-plough of diamond-like hardness, what allows the definition of highly transparent Josephson junctions. Additionally a dc-SQUID is fabricated to verify appropriate functioning of the junctions. The devices are easily integrated in mesoscopic devices as local radiation sources and can be used as tunable on-chip millimeter wave sources.