How optical excitation controls the structure and properties of vanadium dioxide.

Autor:	Otto MR; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, QC, Canada H3A 2T8; martin.otto@mail.mcgill.ca., René de Cotret LP; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, QC, Canada H3A 2T8., Valverde-Chavez DA; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, QC, Canada H3A 2T8., Tiwari KL; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, QC, Canada H3A 2T8., Émond N; Institut National de la Recherche Scientifique, Centre Énergie Matériaux et Télécommunications, Université du Québec, Varennes, QC, Canada J3X 1S2., Chaker M; Institut National de la Recherche Scientifique, Centre Énergie Matériaux et Télécommunications, Université du Québec, Varennes, QC, Canada J3X 1S2., Cooke DG; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, QC, Canada H3A 2T8., Siwick BJ; Department of Physics, Center for the Physics of Materials, McGill University, Montreal, QC, Canada H3A 2T8.; Department of Chemistry, McGill University, Montreal, QC, Canada H3A 0B8.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2019 Jan 08; Vol. 116 (2), pp. 450-455. Date of Electronic Publication: 2018 Dec 26.
DOI:	10.1073/pnas.1808414115
Abstrakt:	We combine ultrafast electron diffraction and time-resolved terahertz spectroscopy measurements to link structure and electronic transport properties during the photoinduced insulator-metal transitions in vanadium dioxide. We determine the structure of the metastable monoclinic metal phase, which exhibits antiferroelectric charge order arising from a thermally activated, orbital-selective phase transition in the electron system. The relative contribution of the photoinduced monoclinic and rutile metals to the time-dependent and pump-fluence-dependent multiphase character of the film is established, as is the respective impact of these two distinct phase transitions on the observed changes in terahertz conductivity. Our results represent an important example of how light can control the properties of strongly correlated materials and demonstrate that multimodal experiments are essential when seeking a detailed connection between ultrafast changes in optical-electronic properties and lattice structure. Competing Interests: The authors declare no conflict of interest.
Databáze:	MEDLINE
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