Enhanced photosusceptibility near Tc for the light-induced insulator-to-metal phase transition in vanadium dioxide

We use optical-pump terahertz-probe spectroscopy to investigate the near-threshold behavior of the photoinduced insulator-to-metal (IM) transition in vanadium dioxide thin films. Upon approaching Tc a reduction in the fluence required to drive the IM transition is observed, consistent with a softeni...

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Bibliographic Details
Published in:Physical review letters 2007-11, Vol.99 (22), p.226401-226401
Main Authors: Hilton, D J, Prasankumar, R P, Fourmaux, S, Cavalleri, A, Brassard, D, El Khakani, M A, Kieffer, J C, Taylor, A J, Averitt, R D
Format: Article
Language:English
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Summary:We use optical-pump terahertz-probe spectroscopy to investigate the near-threshold behavior of the photoinduced insulator-to-metal (IM) transition in vanadium dioxide thin films. Upon approaching Tc a reduction in the fluence required to drive the IM transition is observed, consistent with a softening of the insulating state due to an increasing metallic volume fraction (below the percolation limit). This phase coexistence facilitates the growth of a homogeneous metallic conducting phase following superheating via photoexcitation. A simple dynamic model using Bruggeman effective medium theory describes the observed initial condition sensitivity.
ISSN:0031-9007
DOI:10.1103/PhysRevLett.99.226401