Rotational coherence spectroscopy of molecules in helium nanodroplets: Reconciling the time and the frequency domains

Abstract

Alignment of OCS, CS${}_2$ and I${}_2$ molecules embedded in helium nanodroplets is measured as a function of time following rotational excitation by a non-resonant, comparatively weak ps laser pulse. The distinct peaks in the power spectra, obtained by Fourier analysis, are used to determine the rotational, B, and centrifugal distortion, D, constants. For OCS, B and D match the values known from IR spectroscopy. For CS${}_2$ and I${}_2$, they are the first experimental results reported. The alignment dynamics calculated from the gas-phase rotational Schrödinger equation, using the experimental in-droplet B and D values, agree in detail with the measurement for all three molecules. The rotational spectroscopy technique for molecules in helium droplets introduced here should apply to a range of molecules and complexes.

arXiv commentASC and LC contributed equally. 7 pages, 3 figures

References in corpus (17)

• Spectroscopy and dynamics in helium nanodroplets
• Rotation of quantum impurities in the presence of a many-body environment
• Potential of a neutral impurity in a large ${}^4$He clusters
• Impulsive Laser Induced Alignment of Molecules Dissolved in Helium Nanodroplets
• Orientation and Alignment Echoes
• Laser-induced rotation of iodine molecules in He-nanodroplets: revivals and breaking-free
• Roton-Rotation Coupling of Acetylene in ${}^4$He
• Long-lasting field-free alignment of large molecules inside helium nanodroplets
• Strongly aligned molecules inside helium droplets in the near-adiabatic regime
• Rotation in liquid ${}^4$He: Lessons from a toy model
• Echo Spectroscopy in multi-level quantum-mechanical rotors
• Wave packet dynamics of potassium dimers attached to helium nanodroplets
• Hyperfine-Structure-Induced Depolarization of Impulsively Aligned ${\mathrm{I}}_2$ Molecules
• Long-lived nuclear coherences inside helium nanodroplets
• Laser-induced dynamics of molecules with strong nuclear quadrupole coupling
• Probing molecular potentials with an optical centrifuge
• The effect of nuclear-quadrupole coupling in the laser induced alignment of molecules

Cited by in corpus (9)

• Femtosecond rotational dynamics of D${}_2$ molecules in superfluid helium nanodroplets
• Nonadiabatic Laser-Induced Alignment Dynamics of Molecules on a Surface
• Laser-induced Coulomb explosion imaging of \ce{(C6H5Br)2} and \ce{C6H5Br-I2} dimers in helium nanodroplets using the Timepix3
• Excited rotational states of molecules in a superfluid
• Topological charges of periodically kicked molecules
• A simple model for high rotational excitations of molecules in a superfluid
• Ultraslow optical centrifuge with arbitrarily low rotational acceleration
• A quantum-chemical perspective on the laser-induced alignment and orientation dynamics of the CH${}_3$X (X = F, Cl, Br, I) molecules
• Interaction quenches in Bose gases studied with a time-dependent hypernetted-chain Euler-Lagrange method