title: Photoinduced phase transition in VO2 nanocrystals: ultrafast control of surface-plasmon resonance.
abstract: We study the ultrafast insulator-to-metal transition in nanoparticles of VO2, obtained by ion implantation and self-assembly in silica. The nonmagnetic, strongly correlated compound VO2 undergoes a reversible phase transition, which can be photoinduced on an ultrafast time scale. In the nanoparticles, prompt formation of the metallic state results in the appearance of surface-plasmon resonance. We achieve large, ultrafast enhancement of optical absorption in the near-infrared spectral region that encompasses the wavelength range for optical-fiber communications. One can further tailor the response of the nanoparticles by controlling their shape.
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA. mrini@lbl.gov
authors.forename: Matteo
authors.initials: M
authors.lastname: Rini
authors.forename: Andrea
authors.initials: A
authors.lastname: Cavalleri
authors.forename: Robert W
authors.initials: RW
authors.lastname: Schoenlein
authors.forename: René
authors.initials: R
authors.lastname: López
authors.forename: Leonard C
authors.initials: LC
authors.lastname: Feldman
authors.forename: Richard F
authors.initials: RF
authors.lastname: Haglund
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Boatner
authors.forename: Tony E
authors.initials: TE
authors.lastname: Haynes