Laser-assisted two-color two-photon double ionization of helium atoms

Xiaofan Zhang,Qing Liao,Ye Li,Zhizhen Zhu,Zhe Wang,Feng Wang,Kai Li ,Meiyan Qin

doi:10.1007/s11082-021-03266-3

Abstract

Correlated momentum and kinetic energy distributions of two photoelectrons in laser-assisted two-color two-photon double ionization of helium are investigated by numerically solving a one-plus-one dimensional time-dependent Schrödinger equation (TDSE). We find that the weak assisting laser field can act as an energy transferring field, resulting in burst of double ionization triggered by the intense extreme ultraviolet (XUV) pulse. More importantly, the participation of the laser photon into the double ionization reshapes the correlation patterns in the momentum and kinetic energy distributions. The laser photon can be absorbed by any one of the two electrons, providing two channels that induces destructive interference in the correlated momentum and kinetic energy distributions, which is never found in previous work.

Highlights

Electron correlation plays a very important role in nonsequential double ionization of atoms and has received extensive investigations in the past three decades [1, 2, 3, 4, 5, 6]
Zhizhen Zhu1 et al In two-color two-photon double ionization, the double ionization process can be divided into two steps, if the double ionization is triggered by absorption of one XUV photon and the subsequent correlation dynamics of the two photoelectrons is perturbed by the weak laser field through additional onelaser-photon absorption or emission
We present the quantum-mechanically calculated momentum and kinetic energy distributions of the two photoelectrons in double ionization of helium atoms driven by an XUV pluse and a weak laser pulse

Summary

Introduction

Electron correlation plays a very important role in nonsequential double ionization of atoms and has received extensive investigations in the past three decades [1, 2, 3, 4, 5, 6]. The behind physical processes of double ionization of helium atoms are still complicated, since they depends strongly on the parameters of the driven pulses. In two-color two-photon double ionization, the double ionization process can be divided into two steps, if the double ionization is triggered by absorption of one XUV photon and the subsequent correlation dynamics of the two photoelectrons is perturbed by the weak laser field through additional onelaser-photon absorption or emission. We present the quantum-mechanically calculated momentum and kinetic energy distributions of the two photoelectrons in double ionization of helium atoms driven by an XUV pluse and a weak laser pulse. The correlation patterns changes with the central photon energy of the XUV pulse. By analyzing the features of the correlation pattern, we draw different photoelectron-laser-photon interaction pictures

Numerical Model

Results and Discussions

Conclusion