Thin-Film Aluminum Microstructure as a Hot-Electron Microwave Radiation Detector

TL;DR

This paper investigates thin-film aluminum structures with micron-sized islands connected by narrow isthmuses, demonstrating their ability to modify properties under microwave radiation and function as highly sensitive microwave detectors at cryogenic temperatures.

Contribution

It introduces a novel aluminum microstructure that acts as a hot-electron microwave detector with high sensitivity, revealing structural and electrical property changes under microwave exposure.

Findings

Structures turn into N-S-N configuration at 4.2 K.

Sensitivity of the detector reaches 10^5 V/W.

Electrical characteristics change under low power microwave radiation.

Abstract

We have found that the thin film aluminum structures shaped into a chain of micron sized islands connected by narrow isthmuses, can modify their electrical and structural properties under microwave radiation. As a result, at the temperature of 4.2 K the film structures turn into a kind of lateral periodic structure N-S-N, where N is for normal islands, S is for superconducting isthmuses. Current-voltage characteristics of the samples, as well as changes of these characteristics under low power radiation, have been studied over the temperature range from 1.3 to 10 K. The sensitivity of a structure as a microwave detector runs 10^{5} V/W.