New microwave detector employing Nb/GaAs super-Schottky contact

It is found that the Nb/GaAs super-Schottky contact diode described here is a promising microwave detector having an extremely high sensitivity, a high reliability, and a compatibility with conventional crystal detectors. It is also found that high vacuum electron-beam deposition is extremely effective in fabricating good superconducting Nb thin film. Preliminary experiments with the diodes show excellent characteristics as a microwave detector. An operational temperature of 4.2 K is characteristic of the diode. It is noted that the diodes have maintained the same characteristics for more than 10 months without any degradation through several tens of heat cycles.