Ultrafast electron-lattice coupling dynamics in VO2 and V2O3 thin films
| Autor: | Ivan K. Schuller, Richard D. Averitt, Juan Gabriel Ramírez, Salinporn Kittiwatanakul, Jiwei Lu, Jingdi Zhang, Stephanie N. Gilbert Corder, Elsa Abreu, Siming Wang, Kevin G. West, Stuart A. Wolf, Mengkun Liu, Hyun-Tak Kim, Sun Jin Yun |
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| Rok vydání: | 2017 |
| Předmět: |
Phase transition
Materials science Phonon Anharmonicity Vanadium chemistry.chemical_element 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Crystallography Sesquioxide chemistry Lattice (order) 0103 physical sciences Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Spectroscopy |
| Zdroj: | Physical Review B. 96 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | Ultrafast optical pump--optical probe and optical pump--terahertz probe spectroscopy were performed on vanadium dioxide (${\mathrm{VO}}_{2}$) and vanadium sesquioxide (${\mathrm{V}}_{2}{\mathrm{O}}_{3}$) thin films over a wide temperature range. A comparison of the experimental data from these two different techniques and two different vanadium oxides, in particular a comparison of the spectral weight oscillations generated by the photoinduced longitudinal acoustic modulation, reveals the strong electron-phonon coupling that exists in both materials. The low-energy Drude response of ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ appears more amenable than ${\mathrm{VO}}_{2}$ to ultrafast strain control. Additionally, our results provide a measurement of the temperature dependence of the sound velocity in both systems, revealing a four- to fivefold increase in ${\mathrm{VO}}_{2}$ and a three- to fivefold increase in ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$ across the insulator-to-metal phase transition. Our data also confirm observations of strong damping and phonon anharmonicity in the metallic phase of ${\mathrm{VO}}_{2}$, and suggest that a similar phenomenon might be at play in the metallic phase of ${\mathrm{V}}_{2}{\mathrm{O}}_{3}$. More generally, our simple table-top approach provides relevant and detailed information about dynamical lattice properties of vanadium oxides, paving the way to similar studies in other complex materials. |
| Databáze: | OpenAIRE |
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