Gap measurement in Nb/NbO/sub x//Al injection controlled planar three terminal devices

The characteristics of Nb/NbO/sub x//Al injection-controlled planar three-terminal superconducting devices (injection-controlled links) have been studied experimentally. A built-in Nb/AlO/sub x//Nb Josephson junction is used to perform direct tunneling measurement, whose results show that the gap in the Nb strip decreases as its critical current is suppressed. It is also shown that the static characteristics of the devices with high and low injector resistance can be fitted to a simple heating model and a modified heating model, respectively.>