Enhanced double ionization rate from O₂ molecules driven by counter-rotating circularly polarized two-color laser...

Area of Science:

• Atomic and Molecular Physics
• Quantum Optics
• Laser-Matter Interactions

Background:

• Nonsequential double ionization (NSDI) is a fundamental process in strong-field physics.
• Understanding NSDI mechanisms is crucial for controlling electron emission from molecules.
• Molecular targets like O2 present complex dynamics due to their electronic structure.

Purpose of the Study:

• To investigate the enhancement of NSDI probability in an O2 target.
• To explore the role of tailored laser fields in manipulating ionization dynamics.
• To analyze the influence of field parameters on electron behavior and ionization yield.

Main Methods:

• Utilizing a counter-rotating circularly polarized two-color laser field (fundamental frequency and its third harmonic).
• Simulating the interaction of the laser field with an O2 molecule.
• Analyzing the resulting electron trajectories and ionization probabilities.

Main Results:

• Significant enhancement of NSDI probability observed in O2.
• The combined electric field forms a four-leaf-clover pattern, increasing electron-molecule collision chances.
• Enhancement is particularly evident in low-intensity fields and across a broad range of field ratios.

Conclusions:

• A counter-rotating two-color laser field can effectively enhance NSDI in O2.
• The unique field geometry facilitates increased electron rescattering, boosting NSDI.
• The study highlights the tunability of NSDI yield by adjusting the laser field parameters.