We combine experimental and theoretical approaches to explore excited rotational states of molecules embedded in helium nanodroplets using CS2 and I2 as examples. Laser-induced nonadiabatic molecular alignment is employed to measure spectral lines for rotational states extending beyond those initially populated at the 0.37 K droplet temperature. We construct a simple quantum-mechanical model, based on a linear rotor coupled to a single-mode bosonic bath, to determine the rotational energy structure in its entirety. The calculated and measured spectral lines are in good agreement. We show that the effect of the surrounding superfluid on molecular rotation can be rationalized by a single quantity, the angular momentum, transferred from the molecule to the droplet.
Physical Review A
I.C. acknowledges the support by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 665385. G.B. acknowledges support from the Austrian Science Fund (FWF), under project No. M2461-N27. M.L. acknowledges support by the Austrian Science Fund (FWF), under project No. P29902-N27, and by the European Research Council (ERC) Starting Grant No. 801770 (ANGULON). H.S acknowledges support from the European Research Council-AdG (Project No. 320459, DropletControl) and from The Villum Foundation through a Villum Investigator grant no. 25886.
Cherepanov I, Bighin G, Schouder CA, et al. Excited rotational states of molecules in a superfluid. Physical Review A. 2021;104(6). doi:10.1103/PhysRevA.104.L061303
Cherepanov, I., Bighin, G., Schouder, C. A., Chatterley, A. S., Albrechtsen, S. H., Muñoz, A. V., … Lemeshko, M. (2021). Excited rotational states of molecules in a superfluid. Physical Review A. American Physical Society. https://doi.org/10.1103/PhysRevA.104.L061303
Cherepanov, Igor, Giacomo Bighin, Constant A. Schouder, Adam S. Chatterley, Simon H. Albrechtsen, Alberto Viñas Muñoz, Lars Christiansen, Henrik Stapelfeldt, and Mikhail Lemeshko. “Excited Rotational States of Molecules in a Superfluid.” Physical Review A. American Physical Society, 2021. https://doi.org/10.1103/PhysRevA.104.L061303.
I. Cherepanov et al., “Excited rotational states of molecules in a superfluid,” Physical Review A, vol. 104, no. 6. American Physical Society, 2021.
Cherepanov I, Bighin G, Schouder CA, Chatterley AS, Albrechtsen SH, Muñoz AV, Christiansen L, Stapelfeldt H, Lemeshko M. 2021. Excited rotational states of molecules in a superfluid. Physical Review A. 104(6), L061303.
Cherepanov, Igor, et al. “Excited Rotational States of Molecules in a Superfluid.” Physical Review A, vol. 104, no. 6, L061303, American Physical Society, 2021, doi:10.1103/PhysRevA.104.L061303.