Coherent control of a resonance lifetime with laser pulses

Effect of the intermolecular excitation in the vibrational predissociation dynamics of van der Waals complexes and the implications for control

The effect of intermolecular excitation on the vibrational predissociation lifetime is investigated systematically for different vdW complexes Rg-X2(B, v') (Rg = rare gas atom, X = halogen atom) by means of wave packet simulations. The lifetime as a function of intermolecular excitation displays a pattern of maxima and minima, with a similar shape for the different Rg-X2(B, v') complexes. The pattern is consistent with previous experimental findings involving lifetimes of intermolecular excitations in similar systems. The structure of the lifetime pattern is found to be determined by the shape of the resonance wave functions in the two van der Waals degrees of freedom, and more specifically by the magnitude of the overlap between the wave function and the coupling responsible for predissociation. Lifetime maxima and minima are associated with minima and maxima of this overlap, respectively. Implications for control of the complex lifetime are discussed.

Resonant detection of the signature of control of a resonance state lifetime using a pump–probe scheme

Realistic wave packet simulations demonstrate that the signature of control of the survival probability and lifetime of a specific resonance state can be observed and probed in typical time-resolved pump–probe experiments.

Selective coherent control of the lifetime of a resonance state with laser pulses

It is shown that new possibilities for control of the lifetime of a system in a resonance state emerge when the density of resonances overlapping and interfering with the target resonance increases. When using a control scheme combining two pump laser pulses, it is found that increasing the density of resonance states overlapping with the target one increases the selectivity of the scheme applied, and leads to achieve a remarkably higher degree of control. Lifetime enhancements by factors up to 20 are obtained when this selectivity is applied. The underlying reasons for such strong enhancements are analyzed and explained in the light of the equations of the model applied. Application of this strategy to control and enhance the lifetime of a system in excited states is envisioned.