Two bosonic quantum walkers in one-dimensional optical lattices

Dynamical properties of two bosonic quantum walkers in a one-dimensional lattice are studied theoretically. Depending on the initial state, interactions, lattice tilting, and lattice disorder, a plethora of different behaviors are observed. Particularly, it is shown that the two bosons' system manifests the many-body-localization-like behavior in the presence of a quenched disorder. The whole analysis is based on a specific decomposition of the temporal density profile into different contributions from singly and doubly occupied sites. In this way the role of interactions is extracted. Since the contributions can be directly measured in experiments with ultracold atoms in optical lattices, the predictions presented may have some importance for an upcoming experiment.