Control of (1+1′)-photondissociation in NaH

Abstract

We have studied -photon dissociation of the NaH molecule (ab initio) from thev = 0 level of the groundelectronic state (X 1Σ+) to therepulsive B 1Π state via thebound intermediate A 1Σ+ state. By solving the one-dimensional time-dependent Schrödinger equation for nuclearmotion using the Fourier grid technique we have shown that the maximum of the-photon dissociation cross section and the shape of the dissociation spectrum can becontrolled by controlling the time delay between the two photoexcitation processes,i.e. bound–bound excitation by the first photon and bound–continuum excitation by thesecond photon respectively. The oscillation of the maximum of the dissociation crosssection with time delay between the two pulses has been shown to be due to theexcitation of different oscillating wavepackets at different delays from the intermediateA 1Σ+ state. It has also been shown that the dissociation spectrum depends on the duration andtemporal profile of the femtosecond pulses used for excitation and hence dissociation can becontrolled by choosing pulses of different shapes and duration. At a particularfrequency of the second pulse, the dissociation cross section oscillates with timedelay and this oscillation in the cross section can be used as a time-dependentquantum gate.