When entanglement harvesting is not really harvesting

We revisit the entanglement harvesting protocol when two detectors are in causal contact. study role of field-mediated communication generating between interacting with a quantum field. provide quantitative estimator relative contribution versus genuine harvesting. For massless scalar fields flat spacetime, we show that can communicate via field, do not really harvest from and instead they get entangled only channel. In other words, these scenarios is truly "harvesting entanglement" field able to communicate. contrast, for massive both contribute equally bipartite causally connected. These results emphasize importance taking into account relationships parties involved this relativistic information before declare it