Classical-Quantum Correspondence for Above-Threshold Ionization

Abstract

We measure high resolution photoelectron angular distributions (PADs) for above-threshold ionization of xenon atoms in infrared laser fields. Based on the Ammosov-Delone-Krainov theory, we develop an intuitive quantum-trajectory Monte Carlo model encoded with Feynman's path-integral approach, in which the Coulomb effect on electron trajectories and interference patterns are fully considered. We achieve a good agreement with the measured PADs of atoms for above-threshold ionization. The quantum-trajectory Monte Carlo theory sheds light on the role of ionic potential on PADs along the longitudinal and transverse direction with respect to the laser polarization, allowing us to unravel the classical coordinates (i.e., tunneling phase and initial momentum) at the tunnel exit for all of the photoelectrons of the PADs. We study the classical-quantum correspondence and build a bridge between the above-threshold ionization and the tunneling theory.

Coulomb-corrected quantum interference in above-threshold ionization: Working towards multitrajectory electron holography

“…Interference between orbits 2 and 3 produces a spider-like interference pattern, which can be seen superimposed on the fingerlike interference pattern that occurs due to interference between orbits 1 and 2. The same spider-like pattern is seen in [55,57], in which the quantum-trajectory Monte Carlo (QTMC) model is applied to mid-IR fields, and experimentally in [32,56], and it is attributed to these forward scattered trajectories. The on-axis contribution of orbit 3 to the overall PADs improves the agreement with the time-dependent Schrödinger equation (TDSE) [26,32,36] and with experiments [13,14,35,56], and can be seen in Coulomb-corrected computations in which orbit 3 has been included implicitly [52,55].…”

“…While our method is similar to other approaches such as the trajectory-based Coulomb-corrected strong-field approximation (TCSFA) [36,37] and the QMTC model [52,55,57], there are some key differences. The TCSFA and the QMTC method solve the forward problem.…”

“…The CQSFA does not suffer from this despite considering sub-barrier Coulomb corrections and orbit 3. The QTMC methods do not contain caustics but are less general as they either disregard sub-barrier corrections [52] or they use quasi-static tunnelling rates [55,57], which will not be valid for higher frequencies [26].…”

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography

“…It is noticed that the exit point shifts toward the atomic core due to the nonadiabatic effect34. According to Feynman’s path integral approach, the phase of the jth electron trajectory in the ensemble is given by the classical action along the trajectory: 2442where p is the asymptotic momentum of the electron. The probability of each asymptotic momentum is determined by…”

“…GQTMC is an extension of the previously used quantum-trajectory Monte Carlo (QTMC) method, which in turn was extended from the classical-trajectory Monte Carlo method212223 by including quantum interference effect after tunneling24. The QTMC method has been widely used to interpret photoelectron spectra in recent years with great success.…”