Collect. Czech. Chem. Commun. 1998, 63, 1089-1093

Probing Weakly-Bound Species with Nonresonant Light: Dissociation of He2Induced by Rotational Hybridization

Břetislav Friedrich, Manish Gupta and Dudley Herschbach

Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, U.S.A.


A field-dependent value of angular momentum can be imparted to a 4He2 cluster by the interaction of its anisotropic polarizability with a nonresonant laser field. In this way a centrifugal term is introduced that can be tuned to a critical value sufficient to overcome the potential that binds the dimer. Due to its dependence on the internuclear distance and laser intensity, the critical angular momentum for dissociation is attained at different internuclear separations for different pulsed-laser intensities. As a result, the dependence of the dissociation probability on the laser intensity offers a means to map the potential and/or the polarizability anisotropy. A comparison with experiment thus could provide a test of either. The technique is applicable to other molecules in bound states close to the dissociation limit.

Keywords: Dissociation; Induced dipole; Clusters; He-Dimer.