Numerical simulation of time delays in lightinduced ionization
Abstract
We apply a fundamental definition of time delay, as the difference between the time a particle spends within a finite region of a potential and the time a free particle spends in the same region, to determine results for photoionization of an electron by an extreme ultraviolet laser field using numerical simulations on a grid. Our numerical results are in good agreement with those of the WignerSmith time delay, obtained as the derivative of the phase shift of the scattering wave packet with respect to its energy, for the shortrange Yukawa potential. In the case of the Coulomb potential we obtain time delays for any finite region, while—as expected—the results do not converge as the size of the region increases towards infinity. The impact of an ultrashort nearinfrared probe pulse on the time delay introduced here is analyzed for both the Yukawa and the Coulomb potential and is found to be small for intensities below 10^{13} W/cm^{2}.
 Publication:

Physical Review A
 Pub Date:
 March 2013
 DOI:
 10.1103/PhysRevA.87.033420
 arXiv:
 arXiv:1211.6476
 Bibcode:
 2013PhRvA..87c3420S
 Keywords:

 33.80.Rv;
 33.80.Wz;
 Multiphoton ionization and excitation to highly excited states;
 Other multiphoton processes;
 Physics  Atomic Physics
 EPrint:
 9 pages, 6 figures