Theoretical study of the ionization of an alkali atom adsorbed on a metal surface by a laser-assisted subfemtosecond pulse

A numerical simulation of the process of ionization of an atom adsorbed on a metal surface by the laser-assisted subfemtosecond pulse is presented. The streaking scheme is considered, when a weak subfemtosecond pulse comes together with a strong IR pulse with a variable delay between them. The process is simulated by solving numerically the nonstationary Schrodinger equation in the cylindrical coordinate system. The double differential cross-sections (DDCS) are computed for a fixed delay between the pulses, but for few different carrier frequencies of the subfemtosecond pulse. The results obtained are compared with those in the gas phase. Beside the conventional streaking shift in energy, the surface influence on the DDCS is revealed. It is shown that the corresponding variation in DDCS noticeably depends on the frequency of the subfemtosecond pulse.