Shakeup excitation during optical tunnel ionization

Area of Science:

• Atomic and Molecular Physics
• Quantum Mechanics
• Strong Field Physics

Background:

• Investigating electron dynamics in intense laser fields is crucial for understanding fundamental atomic and molecular processes.
• Tunnel ionization in strong fields leads to complex electron interactions, including shakeup phenomena.
• The behavior of two-electron systems under extreme electromagnetic conditions remains an active area of research.

Purpose of the Study:

• To theoretically and experimentally investigate the shakeup of a two-electron system in a strong infrared laser field.
• To develop a comprehensive analytical theory for shakeup in intense laser fields.
• To quantitatively measure and compare the shakeup process with theoretical predictions.

Main Methods:

• Development of a complete analytical theory for electron shakeup in intense laser fields.
• Experimental investigation using strong infrared laser fields.
• Utilizing the molecular clock, based on internuclear motion, for experimental shakeup measurement.

Main Results:

• Prediction of the formation of one excited sigma(u) D(+)(2) state per approximately 10(5) ionization events.
• Experimental observation of the predicted shakeup process.
• Quantitative agreement between the number of measured shakeup events and theoretical predictions.

Conclusions:

• The developed analytical theory accurately describes electron shakeup in intense laser fields.
• Experimental validation confirms the theory's predictions for the sigma(u) D(+)(2) state.
• The molecular clock is an effective tool for measuring shakeup phenomena in strong-field atomic physics.