title: Shifts in the ESR spectra of alkali-metal atoms (Li, Na, K, Rb) on helium nanodroplets.
abstract: He-droplet-induced changes of the hyperfine structure constants of alkali-metal atoms are investigated by a combination of relativistically corrected ab initio methods with a simulation of the helium density distribution based on He density functional theory. Starting from an accurate description of the variation of the hyperfine structure constant in the M-He diatomic systems (M=Li, Na, K, Rb) as a function of the interatomic distance we simulate the shifts induced by droplets of up to 10,000 (4)He atoms. All theoretical predictions for the relative shifts in the isotropic hyperfine coupling constants of the alkali-metal atoms attached to helium droplets of different size are then tied to a single, experimentally derived parameter of Rb.
authors.affiliation: Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria. andreas.w.hauser@gmail.com
authors.forename: Andreas W
authors.initials: AW
authors.lastname: Hauser
authors.forename: Thomas
authors.initials: T
authors.lastname: Gruber
authors.forename: Michael
authors.initials: M
authors.lastname: Filatov
authors.forename: Wolfgang E
authors.initials: WE
authors.lastname: Ernst