The quantum transport of vortices in very long and narrow arrays of small Josephson junctions is studied experimentally. We investigate the forming of a Mott insulator in periodic arrays. When the vortex density is commensurate with the one-dimensional periodic potential, the vortices localize due to the strong repulsive vortex-vortex interaction. We explore the influence of interaction strength, bandwidth, sample geometry, and temperature on the stability of the Mott states.

• Received 27 October 1997

DOI:https://doi.org/10.1103/PhysRevB.57.11684