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Optical conversion of conical intersection to avoided crossing.
Yasuki Arasaki1, Kazuo Takatsuka
1Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, 153-8902, Tokyo, Japan.
Physical Chemistry Chemical Physics : PCCP
|February 2, 2010
Summary
External symmetry breaking converts a conical intersection to an avoided crossing in nitrogen dioxide (NO2) molecules. This transformation significantly impacts population transfer during femtosecond laser interactions.
Area of Science:
- Quantum dynamics
- Molecular physics
- Chemical physics
Background:
- Conical intersections are crucial in molecular dynamics, enabling efficient non-adiabatic transitions.
- Symmetry often dictates the presence and nature of conical intersections in molecules.
- Controlling molecular dynamics requires understanding how to manipulate these intersections.
Purpose of the Study:
- To investigate the mechanism of converting a symmetry-allowed conical intersection to an avoided crossing.
- To explore the influence of external symmetry breaking on molecular population transfer.
- To demonstrate this effect using nitrogen dioxide (NO2) under specific laser conditions.
Main Methods:
- Full quantum dynamics simulations were performed.
- Coupled ab initio potential energy surfaces were utilized.
- A phase-controlled far-infrared femtosecond pulse field was applied to NO2.
Main Results:
- Symmetry breaking was successfully introduced via the external laser field.
- The conical intersection in NO2 was converted into an avoided crossing.
- Population transfer dynamics through the modified intersection were significantly altered.
Conclusions:
- External symmetry breaking provides a viable method to control molecular reaction pathways.
- The conversion of conical intersections to avoided crossings offers a new route for manipulating photochemical processes.
- This study highlights the potential of tailored laser fields in controlling quantum dynamics.
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