  Quantum entanglement may have various origins ranging from solely
interaction-driven quantum correlations to single-particle effects. Here, we
explore the dependence of entanglement on time-dependent single-particle basis
transformations in fermionic quantum many-body systems, thus aiming at
isolating single-particle sources of entanglement growth in quench dynamics.
Using exact diagonalization methods, for paradigmatic non-integrable models we
compare to the standard real space cut various physically motivated
bipartitions. Moreover, we search for a minimal entanglement basis using local
optimization algorithms, which at short to intermediate post-quench times
yields a significant reduction of entanglement beyond a dynamical Hartree-Fock
solution. In the long-time limit, we identify an asymptotic universality of
entanglement for weakly interacting systems, as well as a cross-over from
dominant real-space to momentum-space entanglement in Hubbard-models undergoing
an interaction quench. Finally, we discuss the relevance of our findings for
the development of tensor network based algorithms for quantum dynamics.
