  The qubit entanglement induced by quasiparticle excitations in the Heisenberg
spin chain and its relationship to the Bethe Ansatz structure of the eigenmodes
is studied. A phenomenon called entanglement quenching, which suppresses
eigenstate entanglement, is described and shown to be mediated by Goldstone
magnons. Scattering states are characterized by short-range entanglement, and
never exhibit entanglement at the longest range. In contrast, bound states have
complex long-range entanglement structures.
