Vortex plasma and transport in superconducting films with magnetic dots

We consider a superconducting film supplied with a magnetic dot array. The dot magnetization is random and oriented, perpendicular to the film. The co ncentration of the superconducting vortices bound to the dots is a step-lik e function of the dot magnetic flux. The concentration of the unbound vorti ces is an oscillating function of the same variable. The resistivity is det ermined by the thermal drift of the vortices through the corner points of a checker-board formed by positive and negative unbound vortices.