Time-Resolved Near-Field investigation 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 (VO2). In order to make this work possible, we have devised and implemented a method for artifact-free nano-imaging with pulsed laser sources [1]. We observe that the transient metallic state is highly inhomogeneous. Following an ultrafast pumping event an increase in near-field signal occurs, where no significant inhomogeneity is observed for approximately fifteen picoseconds. This is followed by a second stage where significant growth of the photo-induced insulator-to-metal transition is observed to evolve inhomogeniously in real space over hundreds of picoseconds. Finally, the growth saturates after several hundred picoseconds when the photo-induced metallic phase occupies the bulk of the material. Our advances pave a pathway to study a wide range of systems with nanoscopic spatial, and ultrafast temporal resolution.
[1] A. J. Sternbach et. al., "Artifact Free Transient Near-Field Nanoscopy" arXiv:1706.08478v2 (2017)
[1] A. J. Sternbach et. al., "Artifact Free Transient Near-Field Nanoscopy" arXiv:1706.08478v2 (2017)
*Department of Energy (DOE) (DE-SC0018218, DE-SC0012592 and DE-SC0012375); Moore Foundation (GBMF4533).
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Presenters
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Aaron Sternbach
- Columbia Univ
- Columbia University
- Physics, Columbia University