HIGH-TEMPERATURE SUPERCONDUCTING JOSEPHSON VORTEX FLOW TRANSISTORS - NUMERICAL SIMULATIONS AND EXPERIMENTAL RESULTS

Josephson Vortex Flow Transistors (JVFTs) based on high transition tem perature superconductors (HTS)are promising candidates for three-termi nal devices, which may be used e.g. at the interface between supercond ucting and semiconducting electronics. We have investigated the perfor mance of JVFTs based on parallel arrays and on long HTS Josephson junc tions, both theoretically and experimentally. Our numerical simulation results reveal the dependence of the current gain on various device p arameters, such as number of junctions, loop size, and screening param eter beta = L/L-j, where L is the loop inductance and Lj the Josephson inductance of a single junction. We have fabricated various devices u sing symmetrically and asymmetrically injected bias currents. The expe rimental results are in good agreement with our simulation results and it is shown that for asymmetric devices high values of the current ga in above 20 can be obtained for temperatures below 60K.