SIS diodes for radio astronomy

As radioastronomers continue to push their observations to shorter wavelengths and fainter signals, their progress is impeded by a lack of sufficiently sensitive millimeter‐wave receivers capable of operating at frequencies above 100 GHz. But now a spinoff from Josephson‐junction fabrication technology appears to be coming to the rescue. New metallurgical and lithographic techniques developed for Josephson‐effect computers are permitting the construction of superconducting diode junctions that promise to function as high‐frequency photon detectors and heterodyne mixers near the theoretical limits of sensitivity.