Absence of Translational Ordering in Driven Vortex Lattices

By using finite temperature molecular dynamics simulations, we consider the question of the existence of dynamical ordering as a two dimensional vortex lattice is driven through a random background potential. The shape of the current-voltage(I-V) characteristics are qualitatively the same as those seen in experiments on the conventional superconductors 2H-NbSe_{2} and Mo_{77}Ge_{23}. However, in contrast to previous simulations, we find that the lattice has no topological or translational order for any value of the driving but that it does exhibit a high driving phase where long range orientational order exists.