R matrixwithtimedependence theory for ultrafast atomic processes in arbitrary light fields
Abstract
We describe an ab initio and nonperturbative R matrix with timedependence theory for ultrafast atomic processes in light fields of arbitrary polarization. The theory is applicable to complex, multielectron atoms and atomic ions subject to ultrashort (particularly fewfemtosecond and attosecond) laser pulses with any given ellipticity, and it generalizes previous timedependent R matrix techniques restricted to linearly polarized fields. We discuss both the fundamental equations, required to propagate the multielectron wave function in time, as well as the computational developments necessary for their efficient numerical solution. To verify the accuracy of our approach, we investigate the twophoton ionization of He, irradiated by a pair of timedelayed, circularly polarized, femtosecond laser pulses, and compare photoelectron momentum distributions, in the polarization plane, with those obtained from recent timedependent closecoupling calculations. The predictive capabilities of our approach are further demonstrated through a study of singlephoton detachment from F^{} in a circularly polarized, femtosecond laser pulse, where the relative contribution of the co and counterrotating 2 p electrons is quantified.
 Publication:

Physical Review A
 Pub Date:
 November 2018
 DOI:
 10.1103/PhysRevA.98.053442
 arXiv:
 arXiv:1812.00234
 Bibcode:
 2018PhRvA..98e3442C
 Keywords:

 Physics  Atomic Physics
 EPrint:
 16 pages, 3 figures