Routes to nonsequential double ionization

Area of Science:

• Atomic and Laser Physics
• Quantum Mechanics
• Computational Physics

Background:

• Accurate calculation of the S matrix is crucial for understanding complex atomic processes in intense laser fields.
• Existing methods often struggle with many-electron systems, limiting detailed analysis of phenomena like nonsequential double ionization.

Purpose of the Study:

• To develop a novel method for calculating the S matrix in many-electron processes within intense-laser atom physics.
• To apply this method to analyze the total electronic momentum distribution in nonsequential double ionization.
• To compare the method's predictions with experimental data for different atomic species.

Main Methods:

• The proposed method draws an analogy to the strong-field approximation used for one-electron processes.
• Approximations to the classical action are made based on the evolving process scenario.
• These approximations enable the evaluation of the quantum-mechanical S matrix.

Main Results:

• The method was applied to study the total electronic momentum distribution in nonsequential double ionization.
• A rescattering scenario showed good agreement with experimental measurements for neon.
• Comparable agreement was not achieved for helium and argon, suggesting the need for alternative scenarios.

Conclusions:

• The developed S matrix calculation method shows promise for analyzing many-electron dynamics in intense laser fields.
• The rescattering scenario is validated for neon but requires further investigation for helium and argon.
• This work opens avenues for exploring alternative physical scenarios in atomic ionization processes.