DYNAMIC BEHAVIOR OF THE SUPERCURRENT IN MESOSCOPIC JOSEPHSON-JUNCTIONS IN THE PRESENCE OF A NONCLASSICAL ELECTROMAGNETIC-FIELD

The dynamic behavior of the supercurrent in mesoscopic Josephson junct ions interacting with various nonclassical electromagnetic fields (NEM F) is investigated. It is shown that for squeezed number states, squee zed states, and a superposition of two coherent states, the supercurre nt exhibits a collapse and revival (CR) phenomenon that is well known in the context of quantum optics. For coherent states and number state s, this phenomenon does not occur. This CR phenomenon, which is due to the granular nature of the field, is also absent if the field is cons idered classically. The dynamic behavior of the supercurrent fluctuati on is also studied and it is found that, generally, when the fluctuati on is large, the supercurrent exhibits collapses, and, when the fluctu ation is small, the supercurrent exhibits revivals. Finally, the ampli tude of current-voltage steps for various NEMF's are studied in some d etail.