Experimental investigations of Rydberg atoms in the presence of parallel magnetic and electric fields

A complete quasi-hydrogenic diamagnetic manifold is experimentally investigated. The spectra are obtained in a uniform magnetic field by exciting M = O odd Rydberg states of lithium in a one-step process. This experiment provides an experimental confirmation for the existence of the two classes of states previously predicted for the diamagnetic Hamiltonian of atomic hydrogen. The evolution of the structure of the n = 30 M = O manifold of lithium under the influence of an additional electric field parallel to the magnetic field is also investigated. The three experimentally observed classes of states are related to the existence and properties of the approximate integral of motion valid for the hydrogen atom in the presence of weak parallel electric and magnetic fields. Significant alterations present in the lithium spectra are ascribed to the nonhydrogenic character of the s states.