  We calculate the radiative properties for a linear dipole-coupled chain of
qubits. Using the explicit energy eigenstates of the system, we find the
radiation patterns for spontaneous transitions from the one-photon eigenstates
to the ground state of the system. We show that depending on the excitation of
a specific atom, the radiation tends to be focused either along or
perpendicular to the chain. We conclude with a derivation of the total decay
rate of the one-photon eigenstates, and find the interesting result that for
systems where the photon wavenumber is not much larger than the interatomic
spacing, up to 94% of the eigenstates are subradiant, that is, they decay
significantly slower than a single atom in isolation.
