Dynamics of the Sine-Gordon Chain

Abstract

Using a molecular-dynamics technique, we studied some nonequilibrium properties of the sine-Gordon chain in one space dimension. We found a $t^{\frac{4}{3}}$ long-time tail in the mean-square displacement, and self-diffusion is traced back to the motion of kink solitons. It is shown that the propagation of these kinks gives rise to a new excitation branch.