Phase-coherence threshold and vortex-glass state in diluted Josephson-junction arrays in a magnetic field - art. no. 094507

We study numerically the interplay of phase coherence and vortex-glass stat e in two-dimensional Josephson-junction arrays with average rational values of flux quantum per plaquette f and random dilution of junctions. For f = 1/2, we find evidence of a phase-coherence threshold value x(s), below the percolation concentration of diluted junctions x(p), where the superconduct ing transition vanishes. For x(s)<x<x(p) the array behaves as a zero-temper ature vortex glass with nonzero linear resistance at finite temperatures. T he zero-temperature critical currents are insensitive to variations in f in the vortex glass region while they are strongly f dependent in the phase-c oherent region.