  We investigate the protocol of entanglement harvesting, where two spacelike
separated particle detectors extract quantum correlations from a quantum field.
Specifically, we analyze the role of the mass of the field and the energy gap
of the detectors in the protocol. Perhaps surprisingly, we find that there are
regimes in which the entanglement harvested can increase with the mass of the
field by decreasing the noise experienced by the detectors. Finally, we study
the optimal relationship between the gap of the detectors and the other
parameters of the setting that maximizes the entanglement harvested, showing
that a small mass can improve the protocol even in this case.
