Single-vortex-induced voltage steps in Josephson-junction arrays

摘要: We have numerically and analytically studied (ac+dc)-driven Josephson-junction arrays with a single vortex or - antivortex pair present. find single-vortex steps in the voltage versus current (I V) characteristics of array. They correspond microscopically to phase-locked move fixed number plaquettes per period ac driving current. In underdamped we motion doubling on steps. observe subharmonic both overdamped arrays. successfully compare these results phenomenological model non-linear viscosity. The I V characteristic an array displays fractional A possible connection present-day experiments is also discussed.