Helicity-dependent dissociative tunneling ionization of CF₄ in multicycle circularly polarized intense laser fields

Abstract

Dissociative tunneling ionization of tetrafluoromethane (CF4) in circularly polarized ultrashort intense laser fields (35 fs, 0.8×1014 W/cm2, 1035 nm), CF4 → CF4+ + e– → CF3+ + F + e–,...

Asymmetric Dissociative Tunneling Ionization of Tetrafluoromethane in ω − 2ω Intense Laser Fields

“…Interestingly, the calculated asymmetry parameter in Figure 9B has an opposite phase dependence to the experimental results, showing that the dissociative tunneling ionization of CF 4 in the ω -2 ω laser fields cannot be explained by the angular distribution of the tunneling ionization from the HOMO and HOMO-1 alone, although the F (or ) fragments are promptly ejected on the repulsive potentials of the X 2 T 1 and A 2 T 2 states after the tunneling ionization ( Figure 4 ). The present experimental results show a marked contrast to those obtained by recent studies on the dissociative ionization of CF 4 in circularly polarized laser fields (35 fs, 0.8 × 10 14 W/cm 2 , 1,035 nm) ( Fujise et al, 2022 ). The recoil-frame photoelectron angular distribution (RFPAD) showed that the dissociative tunneling ionization occurs more efficiently when the electric field points from F to C than the opposite, which is consistent with the prediction by WFAT for the tunneling ionization (see also Figure 8 ).…”

“…Figure 5A shows the momentum image of that dominates the time-of-flight spectrum, reflecting the repulsive nature of the PES of . The KER spectrum shows a broad single peak at E kin = 0.8 eV as observed in the previous studies ( Tang et al, 2013 ; Larsen et al, 2018 ; Hossen et al, 2018 ; Hikosaka and Shigemasa, 2006 ; Fujise et al, 2022 ). The momentum image in Figure 5A shows an elliptic distribution.…”

“…The process is characterized by the ultrashort lifetime ( 40 fs) ( Pertot et al, 2017 ) on the repulsive PESs leading to the + F asymptote in both the ground and the first excited states of as shown in Figure 4 . The repulsive PESs imply that the CF 4 can serve as a unique benchmark to elucidate how the tunneling ionization of polyatomic molecules proceeds in intense laser fields because fragments can be produced by direct dissociation without additional interaction with the laser fields ( Fujise et al, 2022 ).…”

Dissociative ionization and Coulomb explosion of CH4 in two-color asymmetric intense laser fields

“…It was shown that the asymmetric ejection of the CF 3 + fragment shows a phase shift of Bp with respect to the prediction by the tunneling ionization from HOMO (1t 1 ) and HOMOÀ1 (4t 2 ). 25 The coupling between the two lowest electronic states 26 is suggested as a possible origin of the discrepancy, indicating the importance of postionization effect in ultrafast dissociative ionization associated with the energy difference close to the photon energy. In this study, another tetrahedral molecule, CH 4 , is investigated.…”

All-Electron, Density Functional-Based Method for Angle-Resolved Tunneling Ionization in the Adiabatic Regime

“…without involving wave function evolution, such as the Ammosov-Delone-Krainov (ADK) formula-tion [16], its molecular version [17], the Keldysh-Faisal-Reiss (KFR) model [18,19], and the weak-field asymptotic theory (WFAT) [20][21][22], which may be considered as one of the most successful of this kind of approach (see Ref. [23][24][25] for comparison with experiments).…”