  Natural particle-number entanglement resides between spatial modes in
coherent ultra-cold atomic gases. However, operations on the modes are
restricted by a superselection rule that forbids coherent superpositions of
different particle numbers. This seemingly prevents mode entanglement being
used as a resource for quantum communication. In this paper, we demonstrate
that mode entanglement of a single massive particle can be used for dense
coding and quantum teleportation despite the superselection rule. In
particular, we provide schemes where the dense coding linear photonic channel
capacity is reached without a shared reservoir and where the full quantum
channel capacity is achieved if both parties share a coherent particle
reservoir.
