Darmstadt 2008 – scientific programme

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A: Fachverband Atomphysik

A 21: Atomic systems in external fields

A 21.5: Talk

Thursday, March 13, 2008, 12:15–12:30, 3D

Evidence for quasi Penning resonances in exact quantum spectra of the hydrogen atom in crossed electric and magnetic fields — •Holger Cartarius, Jörg Main, and Günter Wunner — 1. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart

The ionization mechanism of the hydrogen atom in crossed magnetic and electric fields has been investigated, e.g. by application of transition state theory [1], however, a complete physical picture is still lacking. In particular, the existence of transition states localized in the vicinity of the Stark saddle point or so-called “quasi Penning resonances” [2] obtained by quantization using a simple expansion of the potential around the saddle point is unclear. We perform quantum mechanically exact calculations of resonances in the spectrum of the hydrogen atom in crossed external fields. By varying the external field strengths structures are revealed which are surprisingly similar to quasi Penning resonances. We investigate the connection between the approximate solutions and the exact quantum resonances.

[1] C. Jaffé, D. Farrelly, and T. Uzer, Phys. Rev. Lett. 84, 610 (2000); Phys. Rev. A 60, 3833 (1999)

[2] C. W. Clark, E. Korevaar, and M. G. Littman, Phys. Rev. Lett. 54, 320 (1985)