  We study the time-dependent dynamical properties of two-component ultracold
fermions in a one-dimensional optical superlattice by applying the adaptive
time-dependent density matrix renormalization group to a repulsive Hubbard
model with an alternating superlattice potential. We clarify how the time
evolution of local quantities occurs when the superlattice potential is
suddenly changed to a normal one. For a Mott-type insulating state at quarter
filling, the time evolution exhibits a profile similar to that expected for
bosonic atoms, where correlation effects are less important. On the other hand,
for a band-type insulating state at half filling, the strong repulsive
interaction induces an unusual pairing of fermions, resulting in some striking
properties in time evolution, such as a paired fermion co-tunneling process and
the suppression of local spin moments. We further address the effect of a
confining potential, which causes spatial confinement of the paired fermions.
