Origin of strong-field PECD: initial-state versus post-tunneling scattering

Determine whether the primary origin of photoelectron circular dichroism (PECD) observed in strong-field ionization of chiral molecules arises predominantly from post-tunneling scattering in the long-range ionic Coulomb potential or from chiral initial electronic bound states and nonadiabatic tunneling dynamics that imprint momentum offsets at the tunnel exit.

Background

The paper investigates PECD in strong-field ionization using co-rotating and counter-rotating two-color circularly polarized fields for propylene oxide and analyzes sub-cycle dependencies. A central question in the field is whether PECD originates mainly from post-tunneling scattering in the ionic potential or from the properties of chiral initial states and their tunneling dynamics, which could imprint momentum offsets at the tunnel exit. The authors measure three-dimensional momentum distributions and employ a heuristic SFA+CTS model consistent with the initial-state interpretation, but explicitly note that the origin has been debated.