Superdiffusion in strongly coupled 2D Yukawa plasmas

Numerical simulation results for the mass transport by diffusion in dusty plasmas are presented and compared to experimental measurements, e.g. [1, 2]. For a wide range of parameters, an anomalous behaviour of the diffusion process, i.e., ``superdiffusion,'' is shown to exist for monolayer systems. In such superdiffusive systems, the mean-squared displacement does not obey the Einstein relation $\langle \vert \vec r(t) - \vec r(t_0)\vert^2\rangle\sim t^\alpha$ with $\alpha=1$. In contrast, the diffusion exponent is greater than unity on large time scales. The dependence of $\alpha$ on the plasma conditions has been investigated by varying the temperature, the screening and the dissipation in the numerical simulations, thus providing detailed predictions for the superdiffusion process in dusty plasmas [3,4]. In addition, we present results for the persistence of superdiffusion, i.e., we adress the question whether superdiffusion extends to arbitrarily long time scales. [1] B. Liu and J. Goree, \textit{Physical Review Letters} \textbf{100}, 055003 (2008) [2] W.-T. Juan and L. I, \textit{Physical Review Letters} \textbf{80}, 3073 (1998) [3] T. Ott, M. Bonitz, P. Hartmann, subm. to \textit{Physical Review Letters} [4] T. Ott \textit{et al.}, \textit{Physical Review E} \textbf{78}, 026409 (2008)