title: Communication: Creation of molecular vibrational motions via the rotation-vibration coupling.
abstract: Building on recent advances in the rotational excitation of molecules, we show how the effect of rotation-vibration coupling can be switched on in a controlled manner and how this coupling unfolds in real time after a pure rotational excitation. We present the first examination of the vibrational motions which can be induced via the rotation-vibration coupling after a pulsed rotational excitation. A time-dependent quantum wave packet calculation for the HF molecule shows how a slow (compared to the vibrational period) rotational excitation leads to a smooth increase in the average bond length whereas a fast rotational excitation leads to a non-stationary vibrational motion. As a result, under field-free postpulse conditions, either a stretched stationary bond or a vibrating bond can be created due to the coupling between the rotational and vibrational degrees of freedom. The latter corresponds to a laser-induced breakdown of the adiabatic approximation for rotation-vibration coupling.
authors.affiliation: Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Kongens Lyngby, Denmark.
authors.forename: Chuan-Cun
authors.initials: CC
authors.lastname: Shu
authors.affiliation: Department of Chemistry, Technical University of Denmark, Building 207, DK-2800 Kongens Lyngby, Denmark.
authors.forename: Niels E
authors.initials: NE
authors.lastname: Henriksen