  We show that a robust macroscopic atom-molecule dark state can exist in
fermionic systems, which represents a coherent superposition between the ground
molecular BEC and the atomic BCS paired state. We take advantage of the
tunability offered by external laser fields, and explore this superposition for
demonstrating coherent oscillations between ground molecules and atom pairs. We
interpret the oscillation frequencies in terms of the collective excitations of
the dark state.
