Glassy dynamics of Josephon arrays on a dice lattice

In this Letter we study the phase diagram and the approach to the equilibrium of Josephson junction arrays on a dice lattice for two different values of the magnetic frustration ($f=1\mathrm{/}2,1\mathrm{/}3$). In both cases the array unedrgoes a Berezinskii-Kosterlitz-Thouless like phase transition. For the fully frustrated array, $f=1\mathrm{/}2$, we find evidence of a {\em glassy behavior} although the system has {\em no disorder}. For comparison we study dynamics of the array at a different value of frustration ($f=1\mathrm{/}3$) and find no trace of glassy dynamics.