The dependence and magnitude of noise currents in superconducting point contacts on dc current and voltage has been measured. The results are in good agreement with the theoretical predictions of Scalapino and Stephen. As expected, in the shot-noise limit at sufficiently high junction voltage the noise current does not vary with temperature.

• Received 25 June 1970

DOI:https://doi.org/10.1103/PhysRevLett.25.588