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Updated: Jul 26, 2025
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High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
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Optically Induced Multistage Phase Transition in Coherent Phonon-Dominated a-GeTe
Li Chen1, Lin Wang1, Kai Jiang1
1Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics & Advanced Instrument (Ministry of Education), Department of Physics, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.
The Journal of Physical Chemistry Letters
|June 16, 2023
Summary
Ultrafast lasers trigger phase transitions in germanium telluride (a-GeTe) by exciting electrons and altering atomic positions. This research reveals mechanisms for controlling phase-change materials using light.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Quantum Chemistry
Background:
- Ultrafast photoexcitation is crucial for understanding electron-lattice dynamics in solids.
- Photoinduced phase transitions are key phenomena in materials science.
Purpose of the Study:
- To explore nonadiabatic pathways of optically excited amorphous germanium telluride (a-GeTe).
- To investigate how ultrafast lasers induce phase transitions in a-GeTe.
Main Methods:
- Real-time time-dependent density functional theory (TDDFT) simulations.
- Occupation-constrained DFT methods.
- Analysis of carrier excitation and atomic dynamics.
Main Results:
- Short-wavelength lasers induce full-domain carrier excitation; long-wavelength lasers excite lone pair electrons.
- Photodoping modifies the potential energy surface and enables A1 coherent forces.
- Phase reversal of Ge and Te atoms is activated, suppressing Peierls distortion.
Conclusions:
- Ultrafast laser excitation provides a method to engineer phase transitions in a-GeTe.
- The findings offer insights into nonequilibrium phase engineering strategies for phase-change materials.
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