Femtosecond Time-Resolved Nano-Imaging of the Insulator-to-Metal Transition in Vanadium Dioxide

ORAL

Abstract

We have preformed femtosecond time-resolved and nanometer spatially resolved measurements of the insulator-to-metal transition in Vanadium Dioxide (VO$_{\mathrm{2}})$. In order to make this work possible, we have devised and implemented a method for artifact-free nano-imaging with pulsed laser sources. We observe that the transient metallic state is highly inhomogeneous. Following an ultrafast pumping event, a homogeneous increase in near-field signal occurs, which signifies that the initial injection of conduction electrons is homogeneous. This is followed by the inhomogeneous insulator-to-metal transition, which evolves over two distinct timescales from tens to hundreds of picoseconds. Our advances pave a pathway to study a wide range of systems with inhomogeneities properties on the nanoscale with nanoscopic spatial, and ultrafast temporal resolution.

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Authors

  • Aaron Sternbach

    Columbia University Physics Department

  • Kyle Lewis

    University of California, San Diego Physics Department

  • Peter Kissin

    University of California, San Diego Physics Department

  • Tetiana Slusar

    University of Science and Technology School of Advanced Device Technology, Metal-Insulator Transition Creative Research Center ETRI

  • Hyun-Tak Kim

    ETRI in Korea, University of Science and Technology School of Advanced Device Technology, Metal-Insulator Transition Creative Research Center ETRI

  • Richard Averitt

    University of California, San Diego Physics Department, Department of Physics, University of California, San Diego, University of California San Diego

  • Dmitri Basov

    Columbia University Physics Department, Columbia University, Columbia Univ, UC San Diego