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Published on: September 6, 2012
Unusual Rydberg system consisting of a positively charged helium nanodroplet with an orbiting electron
Evgeniy Loginov1, Marcel Drabbels
1Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Abstract:
Evidence is presented of an unusual Rydberg system consisting of a helium nanodroplet containing a positively charged sodium ion and an orbiting electron. Rydberg states of this system with principal quantum number n<20 are found to be unstable on a nanosecond time scale. In contrast, Rydberg states with n≳100 are found to have a lifetime of 1.1 μs. In addition, it is found that the ionization threshold of sodium-doped helium is broadened and redshifted with respect to that of the free atom. These observations are successfully reproduced using a pseudodiatomic description of the system in which the interactions of the sodium and its ion with the helium are calculated as the sum of pair potentials.
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