We study under what circumstances a separable bipartite system A-B can or cannot become entangled through local interactions with a bi-local entangled source $\text{ S}_1$-$\text{ S}_2$. We obtain constraints on the general forms of the interaction Hamiltonians coupling A with $\text{ S}_1$ and B with $\text{ S}_2$ necessary for A and B to become entangled. We are able to generalize and provide non-perturbative insight on several previous no-go theorems of entanglement harvesting from quantum fields using these general results. We also discuss the role of communication in the process of entanglement extraction, establishing a distinction between genuine entanglement extraction and communication-assisted entanglement generation.
Categories: quant-ph gr-qc hep-th