Decay-Induced Interference Effect on Photon Correlation in a Nearly Equispaced Three-Level Ladder Atom

We investigate the effect of decay-induced interference on photon correlation in a nearly equispaced three-level driven ladder atom. It is found that the combination of destructive interference and two-photon resonance are responsible for the occurrence of nonclassical correlations. In addition, the bunching or antibunching behavior of the two emission processes can be controlled by the relative phase of the two applied fields attributed to the phase control spontaneous emission enhancement or cancellation.