  We study the dynamics of doublon in the half-filled Hubbard model on the
triangular lattice by using the cellular dynamical mean field theory.
Investigating the nearest-neighbor dynamical correlations, we demonstrate that
a nearest-neighbor doublon-holon pair shows a strong attraction, in particular
in the insulating phase. We also calculate the on-site dynamical correlation of
doublon and find that the life time of doublon is longer in the metallic phase
than in the insulating phase. In the long-time region, the metallic phase has
persistent fluctuations in various nearest-neighbor configurations, while the
fluctuations are vanishingly small in the insulating phase. Obtained results
indicate clear differences of dynamics of doublon between in the metallic and
in the insulating phases.
