Exploration of the Circularly Polarized Attosecond Pulse Generation Mechanisms by Polarization Gating*

We perform a fully ab initio investigation of the generation of circularly polarized attosecond pulse of atomic H driven by polarization gating. The time-dependent Schrödinger equation is solved accurately and efficiently by means of the time-dependent generalized pseudospectral method. We investigate the physical mechanism of this process by solving the time-dependent Schrödinger equation in the integral form. In this way, the contribution of the wave function from different time segment to the induced dipole can be analyzed. The dynamic behavior during this process can be unveiled by the Bohmian trajectories of the dominant part of the wave function.