Novel two-dimensional arrays of Josephson junctions with short-range and with long-range interaction.

摘要

e report measurements on hybrid (Josephson junction - superconducting wire) arrays and on Josephson junction arrays with long-range interaction. We first study hybrid arrays, which consist of superconducting wires along one direction of a square geometry and Josephson junctions along the perpendicular direction. Our measurements indicate that these devices exhibit either one-dimensional (1D) or two-dimensional (2D) behavior depending on the ratio of the geometrical inductance of the superconducting wires divided by the Josephson inductances of the junctions. By tuning the ratio of the two inductances, we can change the topology of the phase drops in the array. The hybrid geometry displays a clear crossover in the dimensional behavior of the system as the inductance ratio is varied.;We then investigate Josephson junction Arrays with Long-Range Interaction (ALRI), which consist of two perpendicular sets of N parallel superconducting wires, coupled by Josephson junctions at every point of crossing. The most unusual feature of these arrays is that the number of nearest-neighbors scales with system size N, and can therefore be made very large. Systems for which the number of nearest-neighbors is large should be well described by a mean-field theory. A mean-field theory calculation for ALRI predicts that