Offset angles of photocurrents generated in few-cycle circularly polarized laser fields

Photocurrents generated in few-cycle circularly polarized laser fields are investigated by solving the time-dependent Schrodinger equation and by means of classical-trajectory Monte Carlo simulations. After confirming the offset angles of the total final currents and electron spectra to be the same, we illustrate the effects of the Coulomb potential and ground state depletion on the offset angles of the total final current, by analyzing how electrons' trajectories and momenta change with laser intensities. Using various atom systems at different laser wavelengths, we find that the behaviors of currents' offset angles as a function of laser intensities seem to be universal.