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

Abstract

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. © 2013 AIP Publishing LLC. [http://dx

A unified theory of weak-field coherent control of the behavior of a resonance state

“…As discussed in earlier works, [35][36][37][38][39] control of the resonance lifetime is achieved by modifying the shape of the resonance survival probability by means of quantum interference. A resonance wave function c i can be expressed as…”

“…Strategies to control the resonance lifetime based on quantum interference have been suggested in environments of both overlapping and isolated resonance states in the weak-field regime. [35][36][37][38][39] Quantum interference was also the basis of different weak-field control schemes proposed to modify the fragment distribution produced upon resonance decay. [40][41][42][43][44] Some of the above control schemes share the common feature that they apply a pump laser field consisting of two pulses with a time delay between them.…”

“…[40][41][42][43][44] Some of the above control schemes share the common feature that they apply a pump laser field consisting of two pulses with a time delay between them. 36,37,39,[42][43][44] Each of these two pulses is used to excite a different resonance energy in an environment of overlapping resonances, which then interfere. By varying the time delay between the pulses, the resonance interference can be controlled.…”

“…More specifically, if the time delay between the pulses is relatively short, such that the two resonances are simultaneously populated in time, the lifetime of both resonances can be controlled. 36,37,39 However, when the time delay is long enough such that the population of the resonance excited with the first pulse has decayed completely when the other resonance is excited with the second pulse, then the product fragment distribution associated with the first resonance can be modified in the asymptotic time regime. 44 Thus, the time delay applied between pulses is related to the nature and time scale of the resonance property under control.…”

Quantum interference control of an isolated resonance lifetime in the weak-field limit

“…[24][25][26][27] Such control schemes are based on the finding 24 that the lifetime of a specific overlapping resonance state depends strongly on the amplitudes of the other overlapping resonances populated in the superposition. [24][25][26][27] Such control schemes are based on the finding 24 that the lifetime of a specific overlapping resonance state depends strongly on the amplitudes of the other overlapping resonances populated in the superposition.…”