Multiphoton Ionization of Highly Excited Hydrogen Atoms

Abstract

fact that the peak of the experimental spectrum ( Fig. 1) falls midway between the single-and double-transition frequencies, and from previous results on the quadrupole-induced lines, 7 we expect the single and double transitions to contribute roughly equal amounts to the spectrum of Fig. 1. Assuming exactly equal contributions would give l$l=0.42e« 0 4 and l$'l = 0.33etf 0 3 . Finally, we mention other possible induction mechanisms, in addition to the hexadecapolar mechanism. The quadrupole-induced double transitions S 0 (D + S i( 3 )> Si(l) + S 0 (3), and S 0 (2) + S 1 (2), which fall within the linewidth of Fig. 1, can be ruled out. To do this the group of double-S transitions near 5300 cm" 1 (outside Fig. 1) were observed 8 and their intensity compared with the expected intensity of the double-S transitions in question; the latter is expected to be about 5% of the intensity of the lines near 5300 cm" 1 . Since the observed peak of Fig. 1 is about 50% of the intensity of the 5300 cm" 1 lines, we see that the double-S transition mechanism fails, by an order of magnitude, to explain the observed peak. Rough estimates of the dispersion and overlap mechanisms indicate that they too are small. The "level-mixing" mechanism of Herman 9 is estimated to be of importance here only if <£> is of order 0. lea 0 4 or less.

Non-dispersive wave packets in periodically driven quantum systems

“…The theoretical interest in the interaction of Rydberg states of atomic hydrogen with low frequency electromagnetic fields has been triggered by early experiments [135] which showed a surprisingly efficient excitation and subsequent ionization of the atoms by the field. More precisely, a microwave field of frequency ω comparable to the energy difference between the initial atomic state and its nearest neighbor was observed to induce appreciable ionization, for atom-field interaction times of approx.…”

“…8 -is given by eq. (135). In a quantum description, the resonant action coincides with the resonant principal quantum number:…”

“…They are the subject of this section. In most experiments on microwave driven Rydberg atoms, linearly polarized (LP) microwaves have been used [132,133,[135][136][137]. For circular polarization (CP), first experiments were performed for alkali atoms in the late eighties [138,139], with hydrogen atoms following only recently [134].…”

“…Non-dispersive wave-packets are associated with eigenstates localized at the center of this island, at the point (see eqs. (135,169)):…”

Chemical Reactivity Dynamics and Quantum Chaos in Highly Excited Hydrogen Atoms in an External Field: A Quantum Potential Approach

“…Bayfield and Koch [8] first studied the chaotic ionization of hydrogen atoms which has been considered to be very important in atomic theory [1,2,4,5,[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. Sanders and Jensen [4] have studied the chaotic ionization of hydrogen and helium using classical mechanics [4].…”