Rotational dynamics of D2 molecules inside helium nanodroplets is induced by a moderately intense femtosecond (fs) pump pulse and measured as a function of time by recording the yield of HeD+ ions, created through strong-field dissociative ionization with a delayed fs probe pulse. The yield oscillates with a period of 185 fs, reflecting field-free rotational wave packet dynamics, and the oscillation persists for more than 500 periods. Within the experimental uncertainty, the rotational constant BHe of the in-droplet D2 molecule, determined by Fourier analysis, is the same as Bgas for an isolated D2 molecule. Our observations show that the D2 molecules inside helium nanodroplets essentially rotate as free D2 molecules.
@article{arxiv.2201.09281,
title = {Femtosecond rotational dynamics of D$_2$ molecules in superfluid helium nanodroplets},
author = {Junjie Qiang and Lianrong Zhou and Peifen Lu and Kang Lin and Yongzhe Ma and Shengzhe Pan and Chenxu Lu and Wenyu Jiang and Fenghao Sun and Wenbin Zhang and Hui Li and Xiaochun Gong and Ilya Sh. Averbukh and Yehiam Prior and Constant A. Schouder and Henrik Stapelfeldt and Igor N. Cherepanov and Mikhail Lemeshko and Wolfgang Jäger and Jian Wu},
journal= {arXiv preprint arXiv:2201.09281},
year = {2022}
}