Josephson junction with lateral injection as a vortex transistor

Long narrow Josephson junctions with current injection to their long (lateral) sides are examined theoretically. Injection into a finite number of points as well as distributed injection are considered. The external magnetic field effect on the critical current and on the I-V curves is calculated. It is shown that the junction with current injection into many points in parallel is an almost complete analog of a conventional semiconductor transistor, the role of electric charge carriers being played by Josephson vortices carrying a single flux quanta. The use of a vortex transistor as a circuit element of both analog and digital devices is discussed.