QUANTUM FEATURES OF RESONANCE FLUORESCENCE AS PROBES OF 2-ATOM DYNAMIC CORRELATIONS

A system of two colliding neutral or ionized atoms with excited states that exhibit fine-structure splitting is shown to emit resonance fluorescence, the quantum features of which can reveal the collisional dynamical correlations between the atoms. Time-resolved measurements of quantum noise (squeezing properties) of the emitted field are shown to yield detailed information on the dynamical correlations. Notably, they disclose the phase between the dynamically correlated two-atom adiabatic states, which is not available from conventional spectroscopy. Such phase information can be a sensitive probe of collision dynamics. It is also important for the achievement of enhanced selectivity in laser-induced reactive collisions or dissociation, based on controllable coherent superpositions of adiabatic states.