Quantum interference in time-delayed nonsequential double ionization

Abstract

We perform a systematic analysis of quantum interference in nonsequential double ionization focusing on the recollision-excitation with subsequent ionization (RESI) mechanism, employing the strong-field approximation (SFA). We find that interference has a major influence on the shape, localization and symmetry of the correlated electron momentum distributions. In particular, the fourfold symmetry with regard to the parallel momentum components observed in previous SFA studies is broken. Two types of interference are observed and thoroughly analyzed, namely that caused by electron indistinguishability and intra-cycle events, and that stemming from different excitation channels. We find that interference is most prominent around the diagonal and anti-diagonal in the parallel-momentum plane and provide fully analytical expressions for most interference patterns encountered. We also show that this interference can be controlled by an appropriate choice of phase and excited-state geometry. This leads a to myriad of shapes for the RESI distributions including correlated, anti-correlated and ring-shaped.

Role of high ponderomotive energy in laser-induced nonsequential double ionization

“…This especially relates to RESI. Several theoretical models have been proposed to explain the general features of RESI [13,[15][16][17][18][19], however, no clear conclusion exists about the role of Coulomb effects, depletion of the excited state, and on excitation channels. When considering results obtained using ultrashort pulses, the pattern is largely defined by depletion effects [20][21][22], contributions of doubly excited states [23], soft recollisions [24], and quantum interferences of different excitation channels [25].…”

Attoscience in phase space

“…However, these oscillations are washed out if more degrees of freedom are incorporated, due to chaotic transverse dynamics and additional resonances. These oscillations are distinct from those attributed to quantum interference in RESI or molecular NSDI [156][157][158][159][160][161]. Further work is related to NSDI in bichromatic, linearly polarised fields [102], and the dynamics of recollisions in fields with circular polarisation [101,105,106].…”

Above-threshold ionization of helium in the long-wavelength regime: Examining the single-active-electron approximation and the two-electron strong-field approximation

“…For two-electron systems, the SFA has been extensively used in the studies of double ionization (see, e.g., Refs. [14,17,[22][23][24][25]).…”

“…The SFA, also known as the Keldysh-Faisal-Reiss theory [10][11][12], and its modified versions have been extensively applied to investigate both one-electron and two-electron dynamics (see, e.g., Refs. [13][14][15][16][17][18][19][20][21][22][23][24][25]). To our knowledge, the SFA has not been applied for the description of the channel-resolved high-order ATI spectra.…”