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Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Nonadiabatic generation of coherent phonons
Y Shinohara1, S A Sato, K Yabana
1Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan.
The Journal of Chemical Physics
|December 20, 2012
Summary
Time-dependent density functional theory (TDDFT) models coherent optical phonon generation by intense laser pulses in antimony (Sb). While TDDFT captures qualitative phonon features, it struggles with dielectric functions, highlighting areas for model improvement.
Area of Science:
- Computational Physics
- Materials Science
- Quantum Mechanics
Background:
- Time-dependent density functional theory (TDDFT) is a key computational method for studying interactions between matter and strong electromagnetic fields.
- Coherent optical phonon generation via intense laser pulses is a significant phenomenon in crystalline materials.
- Crystalline antimony (Sb) is of interest due to strong phonon coupling and observable optical phonons of various symmetries.
Purpose of the Study:
- To apply TDDFT to investigate coherent optical phonon generation in crystalline antimony (Sb) under intense laser pulse excitation.
- To assess the capability of TDDFT in explaining observed qualitative features of coherent phonons in Sb.
- To compare TDDFT results with a simple dielectric model for nonadiabatic coherent phonon generation.
Main Methods:
- Application of time-dependent density functional theory (TDDFT) to model phonon generation.
- Simulation of coherent optical phonon generation induced by intense laser pulses.
- Examination of nonadiabatic coupling effects in crystalline antimony.
- Development and comparison with a simple dielectric model for phonon generation.
Main Results:
- TDDFT successfully accounts for several qualitative characteristics of observed coherent phonons in antimony.
- The theory demonstrates limitations in accurately reproducing the experimentally observed dielectric functions of Sb.
- Nonadiabatic coupling plays a crucial role in the coherent phonon generation process within Sb.
Conclusions:
- TDDFT provides valuable insights into coherent optical phonon generation, particularly regarding qualitative features in materials like Sb.
- Further refinement of TDDFT is needed to improve its quantitative accuracy for dielectric properties in such systems.
- The study underscores the importance of nonadiabatic effects and provides a comparative analysis with simpler models.
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