SUPERCONDUCTOR-INSULATOR TRANSITION IN 2-DIMENSIONAL DIRTY BOSON SYSTEMS

Universal properties of the zero-temperature superconductor-insulator transition in two-dimensional amorphous films are studied by extensive Monte Carlo simulations of bosons in a disordered medium. We report r esults for both short-range and long-range Coulomb interactions for se veral different points in parameter space. In all cases we observe a t ransition from a superconducting phase to an insulating Bose glass pha se. From finite-size scaling of our Monte Carlo data we determine the universal conductivity sigma and the critical exponents at the transi tion. The result sigma = (0.55+/-0.06)(2e)2/h for bosons with long-ra nge Coulomb interaction is roughly consistent with experiments reporte d so far. We also find sigma = (0.14 +/- 0.03)(2e)2/h for bosons with short-range interactions.