Modelling laseratom interactions in the strong field regime
Abstract
We consider the ionisation of atomic hydrogen by a strong infrared field. We extend and study in more depth an existing semianalytical model. Starting from the timedependent Schrödinger equation in momentum space and in the velocity gauge we substitute the kernel of the nonlocal Coulomb potential by a sum of N separable potentials, each of them supporting one hydrogen bound state. This leads to a set of N coupled onedimensional linear Volterra integral equations to solve. We analyze the gauge problem for the model, the different ways of generating the separable potentials and establish a clear link with the strong field approximation which turns out to be a limiting case of the present model. We calculate electron energy spectra as well as the time evolution of electron wave packets in momentum space. We compare and discuss the results obtained with the model and with the strong field approximation and examine in this context the role of excited states.
Contribution to the Topical Issue "Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces", edited by A.N. GrumGrzhimailo, E.V. Gryzlova, Yu V. Popov, and A.V. Solov'yov.
 Publication:

European Physical Journal D
 Pub Date:
 April 2017
 DOI:
 10.1140/epjd/e2017707078
 arXiv:
 arXiv:1611.04300
 Bibcode:
 2017EPJD...71...97G
 Keywords:

 Physics  Atomic Physics
 EPrint:
 11 pages, 5 figures