Drag dynamics in one-dimensional Fermi systems

Abstract

We study drag dynamics of several fermions in a fermion cloud in one-dimensional continuous systems, with particular emphasis on the nontrivial 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 (DMRG) 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 nontrivial 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.