Delocalization in a partially disordered interacting many-body system

We study a partially disordered one-dimensional system with interacting particles. Concretely, we only impose a disorder potential to every other site, followed by a clean site. The numerical analysis of finite systems reveals that the ergodic regime with a large entanglement extends to higher disorder strengths compared to a fully disordered system. More importantly, at large disorder, there exist eigenstates with large entanglement entropies and significant correlations between the clean sites. These states have almost volume-law scaling, embedded into a sea of area-law states, reminiscent of inverted scar states. These eigenstate features leave fingerprints in the nonequilibrium dynamics even at large disorder regime, with a significant initial state dependence. We demonstrate that certain types of initial charge density wave states decay significantly, while others preserve their initial inhomogeneity as is typical for many-body localized systems. This initial condition-dependent dynamics may give us extra control over the system to study delocalization dynamics at large disorder strength and should be experimentally feasible with ultracold atoms in optical lattices.