QUANTUM EFFECTS IN A SUPERCONDUCTING-GLASS MODEL

We study disordered Josephson-junction arrays with long-range interact ion and charging effects. The model consists of two orthogonal sets of positionally disordered N parallel filaments (or wires) Josephson cou pled at each crossing and in the presence of a homogeneous and transve rse magnetic field. The large charging energy (resulting from small se lf-capacitance of the ultrathin wires) introduces important quantum fl uctuations of the superconducting phase within each filament. Position al disorder and magnetic-field frustration induce spin-glass-like grou nd states, characterized by not having long-range order of the phases. The stability of this phase is destroyed for sufficiently large charg ing energy. We have evaluated the temperature vs charging energy phase diagram by extending the methods developed in the theory of infinite- range spin glasses, in the limit of large magnetic field. The phase di agram in the different temperature regimes is evaluated by using a var iety of methods, to wit: semiclassical WKB and variational methods, Ra yleigh-Schrodinger perturbation theory, and pseudospin effective Hamil tonians. Possible experimental consequences of these results are brief ly discussed.