Article

Femtosecond Structural Dynamics in VO 2 during an Ultrafast Solid-Solid Phase Transition

University of California San Diego, La Jolla, California 92093-0339, USA.
Physical Review Letters (Impact Factor: 7.51). 01/2002; 87(23):237401. DOI: 10.1103/PhysRevLett.87.237401
Source: PubMed

ABSTRACT

Femtosecond x-ray and visible pulses were used to probe structural and electronic dynamics during an optically driven, solid-solid phase transition in ${\mathrm{VO}}_{2}$. For high interband electronic excitation $($\sim${}5\ifmmode\times\else\texttimes\fi{}{10}^{21}{\mathrm{cm}}^{$-${}3})$, a subpicosecond transformation into the high- $T$, rutile phase of the material is observed, simultaneous with an insulator-to-metal transition. The fast time scale observed suggests that, in this regime, the structural transition may not be thermally initiated.

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Available from: Jeff A Squier, Oct 17, 2014
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    • "In the recent monograph[10], it is stated that the metalinsulator transition in VO 2 has a combined nature, having the features of both Mott and Peierls transitions. Nonetheless, many experimental facts indicate that the transition might be initiated by an increase in the free charge carrier density (without heating to T = T t and without affecting the lattice, i.e. not under, for example, doping or pressure) under photo-generation[11], injection[12], or high-field generation at switching[13]. These results evidence that the electron-electron interaction is of importance for a correct description of the transition. "
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