Possible three terminal HTS transistor device

A non-zero, gauge invariant potential /spl mu/ has been recognized since 1972 to occur in superconductors in various non-equilibrium circumstances. It is central to the description of the time dependent properties. Non-zero values of this potential cause gap suppression. Thus if the local value of the potential /spl mu/ can be made sufficiently large, the material can be locally switched into the normal state. Superfluid flow would no longer exist and a voltage would be required to sustain a preexisting current. The S to N switching time is expected to be sub-picosecond for Nb and faster for the HTS materials. The time scale for the restoration of superconductivity will be set by the dynamic branch mixing time, sub-nanosecond for Nb. Thus the main difficulty in designing a superconducting transistor analog using this effect is in producing a sufficiently large value of /spl mu/. We suggest that an appropriate mechanism is provided by the injection of a current of predominantly electron- or hole-like character from a doped non-degenerate semiconductor into a thin, current carrying superconducting film.