RESONANCE MODES IN ONE-DIMENSIONAL PARALLEL ARRAYS OF JOSEPHSON-JUNCTIONS

We investigate both experimentally and numerically the dynamics of dis crete one-dimensional parallel arrays of underdamped Josephson junctio ns. In a magnetic field, measurements show steps in the current-voltag e characteristics which are the discrete analogs of Fiske steps in a l ong Josephson junction. From the position of the steps, one can constr uct a plot of the dispersion relation omega(k). We observe a sine-depe ndence in the dispersion relation due to the discrete nature of our ar rays. We also observe an additional, smaller gap at a k-value determin ed by the periodicity of the vortex lattice. Our measurements are supp orted by numerical simulations of the full dynamics. The Fiske steps p rovide an experimental method to measure the self-inductance of 1D par allel arrays.