Azimuthal asymmetry of the extracted electron in field ionization of a hydrogen atom with orbital angular momentum

摘要

The tunneling ionization of an excited hydrogen atom by a static electric field E is investigated for the case where the initial electron has an orbital angular momentum L nonparallel to E. The outgoing electron has a nonzero mean transverse velocity < v(T)> in the direction of E x < L >. During this process the linear Stark effect makes < L > and < v(T)> oscillate or rotate about E. Measures of the asymmetry are calculated at leading order in E for an initial state 2P state. The generalization to coherent elliptic Rydberg states is outlined. A subset of these states whose classical Kepler ellipses rotate rigidly about E is particularly interesting for the observation of the asymmetry. The preparation of states with L nonparallel to E and the conditions to get a sizable v(T) asymmetry are discussed.