  We exploit the qubit-qubit coupling induced by plasmon-polariton modes in a
one-dimensional nanowaveguide to obtain various two-qubit entanglement
situations. Firstly, we observe three phenomena occurring when preparing the
initial state of the system and leaving it freely relax: spontaneous formation
of entanglement, sudden birth and revival. Then, we show that plugging a laser
to each of the qubit, the system arrives to an steady state which, depending on
their inter-qubit distance, can also be entangled. For this situation, we also
characterize the quantum state of the system showing the entanglement-purity-
diagram typical for two-qubit systems.
