Interaction-controlled impurity transport in trapped mixtures of ultracold bosons

We explore the dynamical transport of an impurity between different embedding majority species, which are spatially separated in a double well. The transfer and storage of the impurity is triggered by dynamically changing the interaction strengths between the impurity and the two majority species. We find a simple but efficient protocol consisting of linear ramps of majority-impurity interactions at designated times to pin or unpin the impurity. Our study of this highly imbalanced few-body triple mixture is conducted with the multilayer mul-ticonfiguration time-dependent Hartree method for atomic mixtures, which accounts for all interaction-induced correlations. We analyze the dynamics in terms of single-particle densities and entanglement growth and provide an effective potential description involving mean fields of the interacting components. The majority components remain self-trapped in their individual wells at all times, which is a crucial element for the effectiveness of our protocol. During storage times each component performs low-amplitude dipole oscillations in a single well. Unexpectedly, the interspecies correlations possess a stabilizing impact on the transport and storage properties

Automated summary

We investigate the dynamic transport of an impurity between different majority species separated in a spatially double well. The impurity transfer and storage are achieved by dynamically changing the interaction strengths between the impurity and the two majority species. We propose a simple and efficient protocol utilizing linear ramps of majority-impurity interactions at specific times to control the impurity. Our study, conducted with the multilayer multiconfiguration time-dependent Hartree method, includes analysis of single-particle densities, entanglement growth, and an effective potential description involving mean fields of the interacting components. The stability of the transport and storage properties is unexpectedly affected by interspecies correlations.