Scaling Analysis of Magnetic-Field-Tuned Phase Transitions in One-Dimensional Josephson Junction Arrays

We have studied the magnetic-field-induced superconductor-insulator quantum phase transition in one-dimensional arrays of small Josephson junctions. We found that the critical magnetic field that separates the two phases corresponds to the onset of Coulomb blockade of Cooper pairs tunneling in the current-voltage characteristics. The resistance data are analyzed in the context of the superfluid-insulator transition in one dimension, and a finite-temperature scaling analysis is performed to extract the critical exponents. The dynamical exponents z are determined to be close to 1, and the correlation length exponents ν are found to be approximately 0.3 and 0.45 in the two groups of measured samples.