Directional correlation in direct and sequential double ionization of model atoms

Area of Science:

• Atomic Physics
• Quantum Mechanics
• Laser-Matter Interactions

Background:

• Understanding the behavior of atoms subjected to intense electromagnetic fields is crucial in atomic physics.
• Double ionization of atoms is a complex process influenced by electron-electron interactions and external fields.
• Previous studies have explored single and double ionization, but the directional dependence and competing mechanisms in two-electron systems require further investigation.

Purpose of the Study:

• To investigate the directional dependence in the time evolution of spatial wavefunctions for two-electron model atoms under intense laser fields.
• To analyze the competing scenarios of simultaneous and sequential double ionization.
• To determine the role of electron-electron repulsion in these competing processes across various laser intensities.

Main Methods:

• Utilizing a two-electron model atom.
• Simulating the system's response to intense laser fields.
• Analyzing the spatial wavefunctions and electron trajectories to identify ionization pathways.
• Varying laser intensities to observe their effect on the ionization dynamics.

Main Results:

• Two distinct competing scenarios for double ionization were identified: simultaneous ejection on the same side and sequential ejection on opposite sides.
• The electron-electron repulsion plays a critical role in determining which ionization pathway dominates.
• Directional dependence in wavefunction evolution, including jet formation, was observed.

Conclusions:

• The study highlights the complex interplay between electron-electron repulsion and external laser fields in driving double ionization.
• The findings provide insights into the fundamental mechanisms governing electron emission from atoms in strong fields.
• The observed directional effects and competing pathways offer a deeper understanding of laser-induced atomic processes.