Photoelectron momentum distributions of single-photon ionization under a pair of elliptically polarized attosecond laser pulses

The attosecond ionization dynamics of atoms has attracted extensive attention in these days. However, the role of the initial state is not clearly understood. To address this question, we perform simulations on the neon atom and its model atom with different initial states by numerically solving the corresponding two-dimensional time-dependent Schro¨dinger equations. We theoretically investigate atomic photoelectron momentum distributions(PMDs) by a pair of elliptically polarized attosecond laser pulses. We find that the PMD is sensitive not only to the ellipticities of the pulses, the relative helicity, and time delay of the pulses, but also to the symmetry of the initial electronic states. Results are analyzed by the first-order time-dependent perturbation theory(TDPT) and offer a new tool for detecting the rotation direction of the ring currents.