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MO: Fachverband Molekülphysik
MO 23: Cluster and Nanoparticles I (joint session MO/A)
MO 23.8: Vortrag
Donnerstag, 13. März 2025, 13:00–13:15, HS XV
Rotational Waver Packet Dynamics of Size-selected Neutral Clusters — •Jiaye Jin, Max Grellmann, Marcel Jorewitz, and Knut R. Asmis — Wilhelm-Ostwald-Institut für Physikalische und Theoretisch Chemie, Universität Leipzig, Leipzig, Germany
We report our results on rotational wave-packet dynamics for the mass-selected neutral clusters in a cryogenic ion trap probed by two-colors femtosecond pump-probe spectroscopy involving the negative-neutral-positive excitation scheme. To achieve this, a rotational wave packet is prepared via photodetachment of mass-selected cold anion using a first linearly polarized laser pulse. The rotation coherence is then probed using a second linearly polarized laser pulse, set either parallel or perpendicular to the polarization of the first pulse, ionizing the neutral molecule. The rotational anisotropy β is then calculated from the cation transients probed at different polarization angles.
Neutral boron cluster B6 is chosen as the first experimental candidate. So obtained time-dependence of B6+ cation measured at parallel probing polarization shows typical J-type recurrences of the initial rotational wave packet at 68 ps, 135 ps, 210 ps and 275 ps. The rotational coherence is confirmed by following measurements using perpendicular polarization, where the recurrent cations signal show opposite intensity compared to the parallel probing. An effect rotational constants is thus obtained by 0.25 cm−1, agreeing well with calculations. These results demonstrate the application in the coherent control for the orientation of mass-selected neutral molecules in a cryogenic ion trap.
Keywords: Ultrafast Dyanmics; Rotational Wave Packet; Ion Trap; Boron Clusters