Critical currents associated with the interaction of commensurate flux-line sublattices in a perforated Al film

The flux-flow critical current as a function of transverse magnetic field for an oxygen-doped Al film perforated with a two-dimensional triangular lattice pattern of holes shows pronounced structure at harmonically related values of the applied magnetic field. Effects at the characteristic fields are interpreted in terms of the interaction between commensurate flux-line sublattices, one of which is strongly pinned to the holes by the vortex-hole coupling force and the other of which is located interstitially between the hole-lattice sites. A model is proposed for the vortex-hole coupling force which, in conjunction with a treatment of vortex-vortex interactions, qualitatively accounts for the observed temperature and field dependence of these harmonically related critical currents