Effect of the clockwise loop of figure 8(a) as applied on v = 11 (panel (a)) or v = 14 (panel (b))

Figure 9. Effect of the clockwise loop of figure 8(a) as applied on v = 11 (panel (a)) or v = 14 (panel (b)). The populations which are plotted are P_{11,11}^{{\rm WP}} by the solid blue line, P_{12,11}^{{\rm WP}} by the dashed red line, for panel (a); and P_{14,14}^{{\rm WP}} by the solid green line, P_{13,14}^{{\rm WP}} by the dashed black line, for panel (b).

Abstract

Laser control schemes for selective population inversion between molecular vibrational states have recently been proposed in the context of molecular cooling strategies using the so-called exceptional points (corresponding to a couple of coalescing resonances). All these proposals rest on the predictions of a purely adiabatic Floquet theory. In this work we compare the Floquet model with an exact wavepacket propagation taking into account the accompanying non-adiabatic effects. We search for signatures of a given exceptional point in the wavepacket dynamics and we discuss the role of the non-adiabatic interaction between the resonances blurring the ideal Floquet scheme. Moreover, we derive an optimal laser field to achieve, within acceptable compromise and rationalizing the unavoidable non-adiabatic contamination, the expected population inversions. The molecular system taken as an illustrative example is H_{2}^{+}.