Control of vibronic excitation using quantum-correlated photons.

We theoretically investigate the two-step excitation of a molecular vibronic state using quantum-correlated photons with time delay in order to control the population of the vibronic excited state. A Morse oscillator having three sets of vibronic states, namely, the ground state, intermediate states, and excited states, is used to evaluate the efficiency of the two-step excitation process. We show that we can efficiently and selectively excite only a target state by using correlated photons and can control the excitation population of the target state by adjusting the delay time of the correlated photons. The potential of controlling a chemical reaction using correlated photons is also discussed.