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.

ASC and LC contributed equally. 7 pages, 3 figures

References in corpus (3)

• Spectroscopy and dynamics in helium nanodroplets
• Rotation of quantum impurities in the presence of a many-body environment
• Wave packet dynamics of potassium dimers attached to helium nanodroplets

Cited by in corpus (6)

• Femtosecond rotational dynamics of D${}_2$ molecules in superfluid helium nanodroplets
• Nonadiabatic Laser-Induced Alignment Dynamics of Molecules on a Surface
• 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
• Interaction quenches in Bose gases studied with a time-dependent hypernetted-chain Euler-Lagrange method