Numerical simulations of strong-field processes in momentum space**Project supported by the National Key Research and Development Program of China (Grant No. 2019YFA0307702), the National Natural Science Foundation of China (Grants Nos. 91850121 and 11674363), the Science Fund of Educational Department of Henan Province of China (Grant No. 2011C140001), and the Ninth Group of Key Disciplines in Henan Province, China (Grant

Abstract

The time-dependent Schrödinger equation (TDSE) is usually treated in the real space in the textbook. However, it makes the numerical simulations of strong-field processes difficult due to the wide dispersion and fast oscillation of the electron wave packets under the interaction of intense laser fields. Here we demonstrate that the TDSE can be efficiently solved in the momentum space. The high-order harmonic generation and above-threshold ionization spectra obtained by numerical solutions of TDSE in momentum space agree well with previous studies in real space, but significantly reducing the computation cost.