Abstract
This paper concerns a new three terminal superconducting weak link device, having a third electrode attached to the weak link part for injecting quasiparticles. The structure, the fabrication procedure and the result of the measurement of its static I-V characteristics are presented. As a result, a current gain larger than that of any other Josephson switching devices is obtained. It is found that the larger current gain depends strongly upon the input resistance between the third electrode and the weak link part. The switching speed of the device is also theoretically discussed.