Glassiness versus Order in Densely Frustrated Josephson Arrays

We carry out extensive Monte Carlo simulations of the Coulomb gas dual to the uniformly frustrated two-dimensional XY model, for a sequence of frustrations f converging to the irrational (3-5) /2. We find in these systems a sharp first order equilibrium phase transition to an ordered vortex structure at a T₂ which varies only slightly with f. This ordered vortex structure remains, in general, phase incoherent until a lower vortex pinning transition T₏ (f) that varies with f. We argue that the glassy behaviors reported for this model in earlier simulations are dynamic effects.