Role of excitation in the electron rotational asymmetry in circularly polarized laser fields

Abstract

We comparatively study electron rotational asymmetries in photoionization of the excited hydrogen atom and photodetachment of the fluorine anion in single circularly polarized laser fields by numerically solving the three-dimensional time-dependent Schrödinger equation (3D-TDSE). We first show that single-photon ionization (or detachment) is more favored for the electron initially corotates with respect to the direction of the laser field. More interestingly, we systematically demonstrate the electron rotational asymmetry of the excited hydrogen atom is completely contrary to that of the fluorine anion in multiphoton ionization (or detachment) regime, which can be attributed to the role played by excited bound states by analyzing the total excitation probability in the excited hydrogen atom. Furthermore, we also confirmed that the electron rotational asymmetry of 2p+ and 2p− degenerate orbitals in the excited hydrogen atom changes when the ionization mechanism switches from three-photon to over-the-barrier.