  We investigate the quasiparticle dynamics in the two-orbital Hubbard model on
the square lattice at quarter filling by means of the cellular dynamical mean
field theory. We show that the Fermi-liquid state is stabilized up to the large
Hubbard interactions in the symmetric case without the Hund's coupling, and
find the heavy quasiparticles around the metal-insulator boundary. It is
elucidated that the Hund's coupling enhances the antiferro-orbital
correlations, which give rise to the pseudo gap behavior in the single-particle
excitations. We also find the nonmonotonic temperature dependence in the
quasiparticle dynamics for intermediate strength of the Hund's coupling, and
clarify that it is caused by the competition between the Fermi-liquid formation
and the antiferro-orbital fluctuations.
