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Updated: Jan 18, 2026
09:49
In Situ Transmission Electron Microscopy with Biasing and Fabrication of Asymmetric Crossbars Based on Mixed-Phased a-VOx
Published on: May 13, 2020
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A Hidden Photoinduced Phase-Transition Pathway in Strain-Engineered VO2
Soon Hee Park1, Jaeku Park1, Hyeong-Do Kim1
1Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, Republic of Korea.
Advanced Materials (Deerfield Beach, Fla.)
|January 17, 2026
Summary
Photoexcitation drives a hidden phase transition in vanadium dioxide (VO2) thin films. The structural change occurs before the electronic insulator-to-metal transition, revealing strain-light coupling for ultrafast control.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Photoexcitation is a key method for inducing nonequilibrium states in quantum materials.
- Vanadium dioxide (VO2) is a prototypical correlated oxide used to study photoinduced insulator-metal transitions.
- The precise sequence of structural and electronic changes in VO2 under photoexcitation is still debated.
Purpose of the Study:
- To investigate the hidden photoinduced transition pathway in epitaxially strained VO2 thin films.
- To determine the temporal order of structural and electronic transitions under photoexcitation.
- To understand the role of lattice dynamics and Mott correlations in nonequilibrium phase transitions.
Main Methods:
- Femtosecond X-ray diffraction to probe transient structural changes.
- Time-resolved terahertz spectroscopy to monitor electronic gap dynamics.
- Fabrication of epitaxially strained VO2 thin films.
Main Results:
- A hidden photoinduced transition pathway was uncovered in strained VO2 films.
- The structural transition, marked by the disappearance of vanadium dimers and dynamic tensile strain, precedes the electronic insulator-metal transition.
- The electronic gap closure occurs after strain relaxation, reversing the canonical temporal order.
Conclusions:
- Lattice dynamics play a crucial role in dictating electronic properties under nonequilibrium conditions, driven by Mott correlations.
- Strain-light coupling emerges as a significant principle for ultrafast control of phase transitions.
- These findings offer new possibilities for developing reconfigurable electronic and photonic devices based on correlated oxides.
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