  We study drag dynamics of several fermions in a fermion cloud in
one-dimensional continuous systems, with particular emphasis on the non-trivial
quantum many-body effects in systems whose parameters change gradually in real
time. We adopt the Fermi--Hubbard model and the time-dependent density matrix
renormalization group method to calculate the drag force on a trapped fermion
cluster in a cloud of another fermion species with contact interaction. The
simulation result shows that a non-trivial peak in the resistance force is
observed in the high cloud density region, which implies a criterion of
effective ways in diffusive transport in a fermion cloud. We compare the DMRG
simulation result with a mean-field result, and it is suggested that some
internal degrees of freedom have a crucial role in the excitation process when
the cloud density is high. This work emphasizes the difference between the
full-quantum calculation and the semiclassical calculation, which is the
quantum effects, in slow dynamics of many-body systems bound in a fermion
cloud.
