Interference-Induced Photon Antibunching in a Cavity QED Setup with a Three-Level Atom

Interference-induced photon antibunching is investigated for a three-level system coupled to a cavity mode, in which the level scheme is of a lambda type. One of the transitions is weakly coupled to the cavity mode while the other is driven by a control field. Without the control field, i.e., in the conventional cavity quantum electrodynamics (QED) scheme in the weak coupling regime, photon antibunching can be achieved by carefully choosing the coupling strength and the detuning. This condition can be alleviated by tuning the strength and the frequency of the control field. The condition for the optimal control field that yields photon blockade is derived, and the effects of changing various parameters are investigated. For a given a set of dissipation rates, the atom-cavity coupling strength g needs to be higher than a certain threshold value, although the whole system still remains in the weak coupling regime. A numerical method for finding the optimal parameter regime is proposed.