Scaling behavior of the magnetic-field-tuned superconductor-insulator transition in two-dimensional Josephson-junction arrays

We have studied the superconductor-insulator (SI) phase transition for two-dimensional (2D) arrays of small Josephson junctions in a weak magnetic field. The data were analyzed within the context of the theory of the magnetic-field-tuned SI transition in 2D superconductors. We show resistance scaling curves over several orders of magnitude for the 2D arrays. The critical exponent zB is determined to be 1.05, in good agreement with the theory. Moreover, the transverse (Hall) resistance at the critical field is found to be very small in comparison to the longitudinal resistance.