DISORDER IN 2-DIMENSIONAL JOSEPHSON-JUNCTIONS

An effective free energy of a two-dimensional (i.e., large area) Josep hson junction is derived, allowing for thermal fluctuations, random ma gnetic fields, and external currents. We show by using replica-symmetr y-breaking methods that the junction has four distinct phases: disorde red, Josephson ordered, a glass phase, and the critical a coexisting J osephson order with the glass phase. Near the coexistence to glass tra nsition at s = 1/2 the critical current is similar to(area)(- S + 1/2) where s is a measure of disorder. Our results may account for junctio n ordering at temperatures well below the critical temperature of the bulk in high-T-c trilayer junctions.