SUPERCONDUCTOR-INSULATOR TRANSITION AND UNIVERSAL RESISTANCE IN JOSEPHSON-JUNCTION ARRAYS IN A MAGNETIC-FIELD

The zero-temperature superconducting transition in a Josephson-junction array with half of a flux quantum per plaquette is considered. Its critical behavior is described by an effective free energy in three dimensions with a transition in a new universality class. From this we infer the critical behavior and the value of the universal resistance at the transition. Relevance of these results to recent experiments on very-small-capacitance arrays is discussed. © 1990 The American Physical Society.