Ionization of atoms in parallel electric and magnetic fields: The role of classical phase space

Abstract

We analyze the influence of classical phase-space structures on the ionization behavior of Rydberg atoms in parallel electric and magnetic fields. Classically, ionization above the Stark saddle-point energy is suppressed for moderate magnetic fields compared to zero magnetic field. The location of a stable periodic orbit in the surface of section serves as a criterion to understand this trend. For strong magnetic fields the effect is reversed, and ionization is enhanced. This fact is related to the onset of global chaos in the Hamiltonian system. We provide an analytic criterion for the field values at which this crossover takes place. ͓S1050-2947͑98͒04011-6͔

Driven Production of Cold Antihydrogen and the First Measured Distribution of Antihydrogen States

“…Some calculations [19,21] and hydrogen measurements [20] (all unfortunately for B 0) give A values ranging between red and blue Stark-shifted values of A 1:8 and 3:6, with a weak n dependence in some cases [19]. This latter value is also close to that for circular Rydberg states in parallel electric and magnetic fields [18]. The dashed distribution midway between the extremes with A 2:7 gives n 65, and the range of possibilities suggests that these n values are uncertain by at least 10%.…”

“…The first difficulty is that n is not a good quantum number in the strong B 5:4 T field, though we still use n as a rough parametrization of binding energy, using E ÿ13:6 eV=n 2 . Ionization likely takes place in the direction of B [18], giving some hope that it may not be strongly modified by B, but this must be investigated.…”

Dynamics of electronic motion in hydrogen atom under parallel strong oscillating magnetic field and intense laser fields

“…Earlier, there had been several studies which investigated the ionization cross-sections of atoms under combined electric and magnetic fields. [21][22][23][24][25] These classical and quantum calculations revealed (i) different ionization regimes depending upon the relative intensities of these external fields, (ii) a possibility of suppression of ionization, and (iii) electron localization. However, none of these studies used the time-dependence of the magnetic field while some of them did consider TD electric fields.…”

Calculation of state selective field ionization of hydrogen atoms in a strong magnetic field

“…There have been several theoretical quantum studies of hydrogen and alkali atoms using advanced numerical techniques to accurately compute properties of this system [9][10][11][12][13][14][15]. Several classical studies of atoms in parallel electric and magnetic fields have contributed to the understanding of the complicated dynamics [16][17][18]. Finally, there have been semiclassical studies that have focussed on the effect of closed classical orbits [19][20][21].…”