Slow relaxation in two-dimensional electron plasma under strong magnetic field

We study slow relaxation processes in a point vortex model for two-dimensional pure electron plasma in the strongly magnetized limit. By numerical simulations, we show that the system settles down to a final state via a slow relaxation after it relaxes into a quasi-stationary state via an initial fast relaxation. By analyzing simulation data, we demonstrate that (i) the system relaxes into the maximum one-body entropy state after the slow relaxation, (ii) the time scale of the slow relaxation in the unit of bulk rotation time increases linearly with the number of electrons, and (iii) each electron undergoes a superdiffusive motion during the slow relaxation process. However, the time scale in which each electron diffuses over the system size turns out to be much shorter than that of the slow relaxation; this suggests that the correlation among the superdiffusive trajectories is important in the slow relaxation process.