Experimental isotope shifts in Stark recurrence spectra of Rydberg D2and H2molecules

Abstract

D${}_{2}$ and H${}_{2}$ Stark recurrence spectra have been measured at scaled energies of $\ensuremath{\epsilon}=\ensuremath{-}2.3$ and $\ensuremath{\epsilon}=\ensuremath{-}3.2$. An isotope shift in the scaled-action locations of recurrence peaks is found and explained by the increased density of states associated with perturbing rotational series. This reinforces the insight gained in previous work on the correspondence between the structures of a quantum spectrum and its classical periodic orbits.