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00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
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01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
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Related Experiment Video
Updated: Jul 19, 2026
10:42
Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
Quantum control of internal conversion in 24-vibrational-mode pyrazine.
P S Christopher1, M Shapiro, P Brumer
1Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
The Journal of Chemical Physics
|October 4, 2006
Summary
Quantum control precisely manipulates internal conversion in pyrazine molecules. This study demonstrates suppressing or accelerating the S(2)-->S(1) transition using a novel quantum dynamics algorithm.
Area of Science:
- Quantum dynamics
- Molecular spectroscopy
- Chemical physics
Background:
- Internal conversion is a key non-radiative decay pathway in molecules.
- Controlling ultrafast molecular processes like internal conversion is crucial for advanced applications.
Purpose of the Study:
- To demonstrate quantum control over the S(2)-->S(1) internal conversion in pyrazine.
- To investigate the role of overlapping resonances in achieving this control.
Main Methods:
- Utilized a complete 24-mode dimensionality model of pyrazine.
- Employed the "QP algorithm" for accurate projected quantum dynamics computations.
- Introduced new diagnostics to analyze resonance contributions.
Main Results:
- Achieved active control, suppressing internal conversion for 50-100 fs (longer than natural ~20 fs).
- Demonstrated acceleration of internal conversion to under 5 fs.
- Showcased superior control in full dimensionality compared to reduced models.
Conclusions:
- Quantum control is effective in manipulating pyrazine's internal conversion.
- Overlapping resonances significantly contribute to successful quantum control.
- Full dimensionality models provide a more accurate representation for enhanced control.