Current-voltage characteristics of shunted Josephson weak links with excess current

Many superconducting Josephson weak link junctions are not adequately or accurately modeled by the resistively shunted junction model. For point contact junctions, step edge junctions and grain boundary junctions, a large excess current in the I-V characteristic is often observed. A new model has been proposed, which provides a more accurate technique of describing the behavior. Using this theory of shunted weak link junctions with excess current, calculations are presented here which accurately describe the magnitude and position of microwave induced current steps in the dc current versus voltage characteristics of such devices.<>