First-order correction terms in the weak-field asymptotic theory of tunneling ionization in many-electron systems

Abstract

The many-electron weak-field asymptotic theory of tunneling ionization including the first-order correction terms in the asymptotic expansion of the ionization rate in field strength was highlighted in our recent fast track communication (Trinh et al 2015 J. Phys. B: At. Mol. Opt. Phys. 48 061003) by demonstrating its performance for two-electron atoms. Here we present a thorough derivation of the first-order terms omitted in the previous publication and provide additional numerical illustrations of the theory.

Electron correlation in tunneling ionization of diatomic molecules: An application of the many-electron weak-field asymptotic theory with a generalized-active-space partition scheme

“…For details on the evaluation of the integral in Eq. (15) and the extraction of the structure factor, see Sec. 2 of the Appendix.…”

“…A more quantitative analysis can be made by considering the Dyson orbital with the asymptotic tail scaled outr 1−Z/κ 0 e κ 0r D(r), which in the limits z → −∞ and x,y → 0 is approximately the integrand in Eq. (15). Thus, for a given molecular orientation β, looking in the direction θ = π − β in the scaled Dyson orbital gives us an indication of the magnitude of the structure factor.…”

“…[30][31][32][33][34] and inclusion of first-order terms in the asymptotic expansion was treated in Refs. [15,35] in the FNA. These extensions will not be considered in this work.…”

“…In the case of molecules, the orientation and internuclear-distance dependences of tunneling ionization introduce further factors wherein electron correlation effects can have an effect, e.g., it is known that the mean-field Hartree-Fock (HF) approximation breaks down at nonequilibrium internuclear distances [13]. To address these challenges, the many-electron weak-field asymptotic theory (ME-WFAT) for tunneling ionization [14,15] was recently developed for arbitrary atoms and molecules in the fixed-nuclei approximation (FNA). The theory generalizes earlier tunneling theories based on the SAEA [5][6][7][8][9].…”

“…In the ME-WFAT, the calculation of the structure factor requires the asymptotic form of the Dyson orbital [14,24]. The only application of the ME-WFAT was on the simplest multielectron atoms H − and He [14,15,24] and the simplest multielectron molecule H 2 [14] aligned with the electric field. Strategies for application of the ME-WFAT on more complicated atomic systems were discussed in Ref.…”