In this talk, I will present our recent work on the applicability of norm-conserving pseudopotentials to intense laser-matter interactions by performing time-dependent density functional theory simulations with an all-electron potential and with norm-conserving pseudopotentials. We find pseudopotentials to be reliable for the simulation of above-threshold ionization over a broad range of laser intensities both for the total ionization probability and the photoelectron energy spectrum. For the simulation of high-order harmonic generation pseudopotentials are shown to be applicable for lower-order harmonics in the spectral range in which the one-photon recombination dipole-matrix element can be recovered by the pseudopotential calculation. With this justification, we are developing a new TDDFT code by using FFT, which can be applied to a large isolate system with 3D grid size of 10⁸. The preliminary results of molecules in an intense laser field by the new method will also be discussed.

Dr. Xiao-Min Tong has been an associate Professor at the Institute of Materials Science and Center for Computational Sciences, University of Tsukuba since 2007. Previously, he was a Research Assistant Professor at the Department of Physics, Kansas State University. He received his B.S. degree from Department of Physics, Peking University in 1984, and his Ph.D in Physics from the Institute of Physics, Chinese Academy of Science in 1988. His research interests have been in the theoretical atomic, molecular and optical physics, especially in the intense laser material interactions. He has authored and co-authored more than 160 refereed papers, which have been cited more than 3,000 times.