Antenna-assisted picosecond control of nanoscale phase transition in vanadium dioxide

Muskens, OL; Bergamini, L; Wang, Y; Gaskell, JM; Zabala, N; de Groot, CH; Sheel, DW; Aizpurua, J

Abstract

Nanoscale devices in which the interaction with light can be configured using external control signals hold great interest for next-generation optoelectronic circuits. Materials exhibiting a structural or electronic phase transition offer a large modulation contrast with multi-level optical switching and memory functionalities. In addition, plasmonic nanoantennas can provide an efficient enhancement mechanism for both the optically induced excitation and the readout of materials strategically positioned in their local environment. Here, we demonstrate picosecond all-optical switching of the local phase transition in plasmonic antenna-vanadium dioxide (VO2) hybrids, exploiting strong resonant field enhancement and selective optical pumping in plasmonic hotspots. Polarization- and wavelength-dependent pump-probe spectroscopy of multifrequency crossed antenna arrays shows that nanoscale optical switching in plasmonic hotspots does not affect neighboring antennas placed within 100 nm of the excited antennas. The antenna-assisted pumping mechanism is confirmed by numerical model calculations of the resonant, antenna-mediated local heating on a picosecond time scale. The hybrid, nanoscale excitation mechanism results in 20 times reduced switching energies and 5 times faster recovery times than a VO2 film without antennas, enabling fully reversible switching at over two million cycles per second and at local switching energies in the picojoule range. The hybrid solution of antennas and VO2 provides a conceptual framework to merge the field localization and phase-transition response, enabling precise, nanoscale optical memory functionalities.

• Journal Article Type: Article
• Acceptance Date: Jun 2, 2016
• Online Publication Date: Jun 3, 2016
• Publication Date: Oct 21, 2016
• Deposit Date: Oct 2, 2018
• Publicly Available Date: Oct 2, 2018
• Journal: Light : Science & Applications
• Print ISSN: 2095-5545
• Electronic ISSN: 2047-7538
• Publisher: Springer Nature [academic journals on nature.com]
• Volume: 5
• Issue: 10
• Pages: e16173
• DOI: https://doi.org/10.1038/lsa.2016.173
• Keywords: Plasmonics, Vo2, Nanoantenna, Insulator-metal Phase Transition
• Publisher URL: https://doi.org/10.1038/lsa.2016.173
• Related Public URLs: https://www.nature.com/lsa/
• Additional Information: Funders : Engineering and Physical Sciences Research Council (EPSRC);Spanish Ministry of Economy and Competitiveness;Department of Industry of the Government of the Basque Country; Projects : ETORTEK IE14-393 NANOGUNE’14;FIS2013-41184-P; Grant Number: EP/J011797/1; Grant Number: EP/J016918/1; Grant Number: IT-756-13