Dynamical study of the superconducting phase transition of two-dimensional networks

Granular aluminum wire networks forming square arrays of N x N ≅ 10/sup 6/ nodes connected by strips 8 μm long were fabricated with photolithographic techniques. For strip resistances of the order of 1kΩ the superconducting transition of the network, as evidenced by ac conductance measurements, is shown to be of the Kosterlitz-Thouless type. In a perpendicular magnetic field, flux quantization in the loops of the network leads to periodic oscillations of the magneto-conductance