Dynamic Melting of the Vortex Lattice

We investigate analytically and numerically the melting of the vortex lattice moving in an inhomogeneous environment under the applied current j. We predict the existence of a dynamic phase transition at some characteristic current j=jₜ (crystallization current) from the motion of the amorphous vortex configuration at j<jₜ to the motion of the vortex crystal at j>jₜ. The crystallization current jₜ exceeds essentially the critical current jc for strongly disordered systems and diverges as temperature approaches the melting temperature Tₘ of the undisturbed lattice.