article published yes Igor Cherepanov author 339C7E5A-F248-11E8-B48F-1D18A9856A87 Giacomo Bighin author 4CA96FD4-F248-11E8-B48F-1D18A9856A870000-0001-8823-9777 Constant A. Schouder author Adam S. Chatterley author Henrik Stapelfeldt author Mikhail Lemeshko author 37CB05FA-F248-11E8-B48F-1D18A9856A870000-0002-6990-7802 MiLe department International IST Doctoral Program project Angulon: physics and applications of a new quasiparticle project A path-integral approach to composite impurities project Recently it became possible to study highly excited rotational states of molecules in superfluid helium through nonadiabatic alignment experiments (Cherepanov et al 2021 Phys. Rev. A 104 L061303). This calls for theoretical approaches that go beyond explaining renormalized values of molecular spectroscopic constants, which suffices when only the lowest few rotational states are involved. As the first step in this direction, here we present a basic quantum mechanical model describing highly excited rotational states of molecules in superfluid helium nanodroplets. We show that a linear molecule immersed in a superfluid can be seen as an effective symmetric top, similar to the rotational structure of radicals, such as OH or NO, but with the angular momentum of the superfluid playing the role of the electronic angular momentum in free molecules. The simple theory sheds light onto what happens when the rotational angular momentum of the molecule increases beyond the lowest excited states accessible by infrared spectroscopy. In addition, the model allows to estimate the effective rotational and centrifugal distortion constants for a broad range of species and to explain the crossover between light and heavy molecules in superfluid 4He in terms of the many-body wavefunction structure. Some of the above mentioned insights can be acquired by analyzing a simple 2 × 2 matrix. https://research-explorer.ista.ac.at/download/11998/12005/2022_NewJournalofPhysics_Cherepanov.pdf application/pdfno https://creativecommons.org/licenses/by/4.0/ IOP Publishing2022 eng 1367-2630 00083921690000110.1088/1367-2630/ac8113 247 Cherepanov I, Bighin G, Schouder CA, Chatterley AS, Stapelfeldt H, Lemeshko M. 2022. A simple model for high rotational excitations of molecules in a superfluid. New Journal of Physics. 24(7), 075004. I. Cherepanov, G. Bighin, C. A. Schouder, A. S. Chatterley, H. Stapelfeldt, and M. Lemeshko, “A simple model for high rotational excitations of molecules in a superfluid,” <i>New Journal of Physics</i>, vol. 24, no. 7. IOP Publishing, 2022. Cherepanov, I., Bighin, G., Schouder, C. A., Chatterley, A. S., Stapelfeldt, H., &#38; Lemeshko, M. (2022). A simple model for high rotational excitations of molecules in a superfluid. <i>New Journal of Physics</i>. IOP Publishing. <a href="https://doi.org/10.1088/1367-2630/ac8113">https://doi.org/10.1088/1367-2630/ac8113</a> Cherepanov, Igor, Giacomo Bighin, Constant A. Schouder, Adam S. Chatterley, Henrik Stapelfeldt, and Mikhail Lemeshko. “A Simple Model for High Rotational Excitations of Molecules in a Superfluid.” <i>New Journal of Physics</i>. IOP Publishing, 2022. <a href="https://doi.org/10.1088/1367-2630/ac8113">https://doi.org/10.1088/1367-2630/ac8113</a>. Cherepanov, Igor, et al. “A Simple Model for High Rotational Excitations of Molecules in a Superfluid.” <i>New Journal of Physics</i>, vol. 24, no. 7, 075004, IOP Publishing, 2022, doi:<a href="https://doi.org/10.1088/1367-2630/ac8113">10.1088/1367-2630/ac8113</a>. I. Cherepanov, G. Bighin, C.A. Schouder, A.S. Chatterley, H. Stapelfeldt, M. Lemeshko, New Journal of Physics 24 (2022). Cherepanov I, Bighin G, Schouder CA, Chatterley AS, Stapelfeldt H, Lemeshko M. A simple model for high rotational excitations of molecules in a superfluid. <i>New Journal of Physics</i>. 2022;24(7). doi:<a href="https://doi.org/10.1088/1367-2630/ac8113">10.1088/1367-2630/ac8113</a> 119982022-08-28T22:02:01Z2025-05-14T11:20:18Z