title: Large enhancement of the vibration-rotation coupling of the nu1 and nu3 states of silane in helium droplets.
abstract: Silane molecules have been embedded in helium droplets and studied via infrared laser depletion spectroscopy in the range of 2190 cm(-1). We found that the R1 and Q2 lines of the nu(3) band have satellites shifted by about 2.3 cm(-1) towards low frequency and having similar intensity to the main lines. We assigned this perturbation in the spectrum to the coupling of the J=2 levels in nu(3) and close lying nu(1) vibration states. The strength of the coupling is a factor of about 50 larger in He droplets than in free molecules and have the same selection rules implied by the tetrahedral symmetry of SiH(4) molecules. The perturbation, which cannot be explained within the framework of a Hamiltonian of free molecules, is evidence of strong coupling of the molecule with some He excitations in the molecular vicinity.
authors.affiliation: DCG Systems, Inc., 45900 Northport Loop East, Fremont, California 94538, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Skvortsov
authors.forename: Daniil
authors.initials: D
authors.lastname: Marinov
authors.forename: Boris G
authors.initials: BG
authors.lastname: Sartakov
authors.forename: Andrey F
authors.initials: AF
authors.lastname: Vilesov