Electron angular correlation in nonsequential double ionization of molecules by counter-rotating two-color circularly...

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Chemistry
• Strong Field Physics

Background:

• Nonsequential double ionization (NSDI) is a fundamental process in strong field physics.
• Understanding electron correlation in NSDI is crucial for probing molecular dynamics.
• Counter-rotating two-color circularly polarized (TCCP) fields offer unique control over ionization dynamics.

Purpose of the Study:

• Investigate electron correlation in molecular NSDI using TCCP fields.
• Analyze the influence of internuclear distance on electron angular correlation.
• Correlate electron correlation behavior with ion momentum distributions.

Main Methods:

• Employed a three-dimensional classical ensemble model for simulations.
• Simulated NSDI of molecules under TCCP laser fields.
• Analyzed electron angular distributions and ion momentum spectra.

Main Results:

• Observed strong angular correlation between emitted electrons in NSDI.
• Demonstrated that electron correlation evolves from correlated to anti-correlated with increasing internuclear distance.
• Identified distinct ion momentum distributions (inverted Y-shape and triangle-shape) corresponding to different internuclear distances.

Conclusions:

• Electron correlation in molecular NSDI is highly sensitive to internuclear distance.
• The transition from correlation to anti-correlation is linked to asymmetric energy sharing and ionization time delays.
• Ion momentum distributions serve as a sensitive probe of electron correlation in TCCP fields.