Electronic cooling of a submicron-sized metallic beam

TL;DR

This paper demonstrates electronic cooling of a submicron-sized metallic beam using superconductor-insulator-normal metal tunnel junctions, achieved through a novel fabrication method that ensures device reliability and effective cooling performance.

Contribution

It introduces a simple, reliable fabrication process for submicron metallic beams with integrated tunnel junctions capable of effective electronic cooling.

Findings

Devices exhibit clear cooling effects up to a factor of two.

The fabrication method is compatible with standard nanofabrication techniques.

Cooling is achieved at sub-kelvin temperatures.

Abstract

We demonstrate electronic cooling of a suspended AuPd island using superconductor-insulator-normal metal tunnel junctions. This was achieved by developing a simple fabrication method for reliably releasing narrow submicron sized metal beams. The process is based on reactive ion etching and uses a conducting substrate to avoid charge-up damage and is compatible with e.g. conventional e-beam lithography, shadow-angle metal deposition and oxide tunnel junctions. The devices function well and exhibit clear cooling; up to factor of two at sub-kelvin temperatures.