  We investigate the time evolution of the quantum meson modes in the late time
of chiral phase transition. In particular, it is shown that there exists a
possible solution to the equation of motion for the quantum meson modes, which
reveals a parametric resonance and/or resonance through forced oscillation
induced by the small oscillation of the chiral condensate. After that, we
demonstrate the unstable regions for the quantum meson modes in both the cases
of a uniform and spatially expanding system.
