Disorder in two-dimensional Josephson junctions

[摘要] An effective free energy of a two-dimensional (i.e., large area) Josephson junction is derived, allowing for thermal fluctuations, random magnetic fields, and external currents. We show by using replica-symmetry-breaking methods that the junction has four distinct phases: disordered, Josephson ordered, a glass phase, and the critical a coexisting Josephson order with the glass phase. Near the coexistence to glass transition 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 junction ordering at temperatures well below the critical temperature of the bulk in high-T-c trilayer junctions.

[关键词] REPLICA SYMMETRY-BREAKING;XY MODEL;FIELD