  We show that, for the purpose of quantum communication via a quantum field,
it is essential to view the field not only as a medium for transmission but
also as a source of entanglement that can aid in the communication task. To
this end, we consider the quantum communication scenario where Alice is
initially entangled with an ancilla and intends to communicate with Bob through
a quantum field, so as to make Bob entangled with the ancilla. We find that if
Alice and Bob communicate by directly coupling to the quantum field, then they
can generate negativity between Bob and the ancilla only at orders that are
higher than second perturbative order. We then present a protocol based on
quantum teleportation in which Alice and Bob consume entanglement that they
obtained from the field via interaction or harvesting. We show that this
protocol can transfer negativity already to second perturbative order.
