  We show how to realize a single-photon Dicke state in a large one-dimensional
array of two- level systems, and discuss how to test its quantum properties.
Realization of single-photon Dicke states relies on the cooperative nature of
the interaction between a field reservoir and an array of two-level-emitters.
The resulting dynamics of the delocalized state can display Rabi-like
oscillations when the number of two-level emitters exceeds several hundred. In
this case the large array of emitters is essentially behaving like a
mirror-less cavity. We outline how this might be realized using a
multiple-quantum-well structure and discuss how the quantum nature of these
oscillations could be tested with the Leggett-Garg inequality and its
extensions.
