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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
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Ultrafast evolution and transient phases of a prototype out-of-equilibrium Mott-Hubbard material.
G Lantz1,2, B Mansart1, D Grieger3
1Laboratoire de Physique des Solides, CNRS, University Paris-Sud, Université Paris-Saclay, 91405 Orsay, France.
Nature Communications
|January 10, 2017
Summary
Ultrafast photoexcitation of V2O3 creates a transient non-thermal phase. This novel state, stabilized by electron-lattice interactions and a unique phonon hardening, offers new pathways for manipulating strongly correlated materials.
Area of Science:
- Condensed matter physics
- Materials science
- Ultrafast spectroscopy
Background:
- Strongly correlated materials exhibit complex phase diagrams and rich out-of-equilibrium dynamics.
- Femtosecond optical pulses enable transient decoupling of electronic and lattice degrees of freedom.
- New material states, inaccessible via quasi-adiabatic methods, can be stabilized.
Purpose of the Study:
- To investigate the out-of-equilibrium behavior of the Mott-Hubbard material V2O3 after ultrafast photoexcitation.
- To characterize the transient phase and its underlying mechanisms.
- To explore the role of electron-lattice interplay in ultrafast material control.
Main Methods:
- Ultrafast optical spectroscopy using femtosecond laser pulses.
- Probing the transient dynamics of V2O3 in both insulating and metallic phases.
- Analysis of coherent phonon behavior (A1g mode).
Main Results:
- A transient non-thermal phase in V2O3 was observed immediately after photoexcitation, persisting for picoseconds.
- Phase formation is initiated by electron excitation into the a1g orbital.
- Lattice distortion leads to hardening of the A1g coherent phonon, contrasting with thermal softening.
Conclusions:
- Selective electron-lattice interplay is crucial for ultrafast control of material properties.
- The observed transient phase and its stabilization mechanism are key to optical manipulation of strongly correlated systems.
- V2O3 serves as a model system for understanding and controlling photoinduced phase transitions.
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