Mechanisms of Strong-Field Double Ionization of Xe

Abstract

We perform a fully differential measurement on strong-field double ionization of Xe by 25 fs, 790 nm laser pulses in intensity region (0.4-3)×10(14) W/cm2. We observe that the two-dimensional correlation momentum spectra along the laser polarization direction show a nonstructured distribution for double ionization of Xe when decreasing the laser intensity from 3×10(14) to 4×10(13) W/cm2. The electron correlation behavior is remarkably different with the low-Z rare gases, i.e., He, Ne, and Ar. We find that the electron energy cutoffs increase from 2.9Up to 7.8Up when decreasing the laser intensities from the sequential double ionization to the nonsequential double ionization regime. The experimental observation indicates that multiple rescatterings play an important role for the generation of high energy photoelectrons. We have further studied the shielding effect on the strong-field double ionization of high-Z atoms.

Channel-Resolved Above-Threshold Double Ionization of Acetylene

“…We hence exclude the mechanism of direct (e, 2e) ionization [39] for the hereobserved nonsequential double ionization. Alternatively, an intermediate doubly excited complex can be formed by multiple inelastic field-assisted recollisions [40][41][42][43][44][45], from which two coherently released electrons share a constant energy as observed in the nonsequential ATDI of argon atoms [20]. We expect a similar scenario of molecular nonsequential ATDI in our linearly polarized pulse, which is mostly sup pressed in a circularly polarized pulse by steering the electron trajectory away from the parent ion.…”

Intensity-dependent two-electron emission dynamics with orthogonally polarized two-color laser fields

“…Despite the great progress on NSDI, new experimental phenomena still constantly emerge and challenge our existing knowledge. Recent examples include the striking anticorrelated electron emission for Ar below the recollision threshold [4], the cross-shaped structure in the correlated two-electron momentum spectrum along the laser polarization direction with near-single cycle laser pulses [5], and the nonstructured momentum distribution of strong-field double ionization of high-Z rare-gas atoms [6].…”

Nonsequential double ionization with mid-infrared laser fields

“…The spectrum shown in Fig. 2(c), with more anti-correlated electron pairs than correlated ones, is a strong indication of the RESI double ionization channel3435. Changing the wavelength to 3200 nm, however, Fig.…”

“…NSDI with near-IR wavelengths has been known to provide an excellent, probably also the simplest, platform for the study of electron correlation effects192021222324252627282930313233343536, which are the foundation for all materials. The questions that we were curious about and trying to answer in this paper include: What do recollision and NSDI processes look like with mid-IR laser fields?…”