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Adiabatic approximation of the correlation function in the density-functional treatment of ionization processes
Physical Review Letters
|December 13, 2006
Summary
This study models helium atom ionization in laser pulses using time-dependent density-functional theory. The method accurately predicts ionization probabilities, including the nonsequential ionization knee.
Area of Science:
- Atomic Physics
- Quantum Mechanics
- Computational Chemistry
Background:
- Investigating atomic ionization in intense laser fields is crucial for understanding light-matter interactions.
- Time-dependent density-functional theory (TDDFT) offers a computationally tractable approach to studying dynamic electronic processes.
Purpose of the Study:
- To investigate the ionization of a one-dimensional model helium atom subjected to short laser pulses.
- To develop and validate a TDDFT approach incorporating electron correlation effects for accurate ionization probability calculations.
Main Methods:
- Utilized a one-dimensional model of the helium atom.
- Employed time-dependent density-functional theory (TDDFT).
- Approximated the correlation function adiabatically, accounting for the derivative discontinuity.
Main Results:
- Calculated ionization probabilities as a function of laser intensity.
- The TDDFT approach successfully reproduced ionization probabilities obtained from solving the time-dependent Schrödinger equation.
- The characteristic 'knee' feature in ionization probabilities, indicative of nonsequential ionization, was reproduced.
Conclusions:
- The developed TDDFT method with an explicit treatment of the derivative discontinuity accurately models atomic ionization dynamics.
- This approach provides a reliable tool for studying nonsequential ionization phenomena in strong laser fields.
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