A microwave operated fast superconducting switch

A superconducting switch was constructed and tested based on the microwave induced transition of a microbridge or long filament into the resistive flux-flow state. Resistance values of the order of 1 kΩ were obtained by connecting in series several microbridges, made of thin films of refractory materials like Nb or Nb3Ge. Due to low power consumption and a lack of electromagnetic interference when used with suitable filters, such switches appear to be well suited in connection with superconducting electronics, incorporating for instance SQUIDs. Results on switching speed, power consumption and crosstalk between the switch and other circuit components located on the same chip are investigated.