AN AC BIASED SUPERCONDUCTING FLUX TRANSFORMER

The coupled motion of the vortex lattices of two electrically insulate d, superimposed, superconducting thin films (primary and secondary) in a perpendicular magnetic field, is predicted to exhibit a Josephson-l ike behavior. For a dc applied current flowing in the primary film, th e voltage difference between the time-averaged primary and secondary f lux flow voltages obeys the equations of a resistively shunted junctio n model. If an ac current is superimposed on the dc current. Shapiro-t ype steps are predicted in the current-voltage characteristic. In cont rast to the conventional Josephson effect, the voltage positions of th ese steps can be tuned by the applied magnetic field.