Quantum interference effects in statistical systems of Josephson junctions in the presence of fluctuations

An experimental study is reported of the interference effects in systems consisting of a large number of superconducting particles coupled by the Josephson forces, the coupling energy beirg comparable with the energy of fluctuations, as in the case of a single junction. The reduction in the coupling energy to the fluctuation level should increase the responsivity of the system to external microwave fields, by analogy with the case of a single junction. Therefore, it would be interesting to consider the possibility of using such systems as sensitive microwave detectors. The experiments were carried out on a niobium powder consistirg of particles about 10 mu in diameter. (auth)