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Article // Increased rise time of electron temperature during adiabatic plasmon focusing

Nature Communications 2017
Created Monday 08 January 2018

Decay of plasmons to hot carriers has recently attracted considerable interest for funda- mental studies and applications in quantum plasmonics. Although plasmon-assisted hot carriers in metals have already enabled remarkable physical and chemical phenomena, much remains to be understood to engineer devices. Here, we present an analysis of the spatio- temporal dynamics of hot electrons in an emblematic plasmonic device, the adiabatic nanofocusing surface-plasmon taper. With femtosecond-resolution measurements, we con- firm the extraordinary capability of plasmonic tapers to generate hot carriers by slowing down plasmons at the taper apex. The measurements also evidence a substantial increase of the “lifetime” of the electron gas temperature at the apex. This interesting effect is inter- preted as resulting from an intricate heat flow at the apex. The ability to harness the “lifetime” of hot-carrier gases with nanoscale circuits may provide a multitude of applications, such as hot-spot management, nonequilibrium hot-carrier generation, sensing, and photovoltaics.

Olga Lozan 1, Ravishankar Sundararaman 2, Buntha Ea-Kim 3, Jean-Michel Rampnoux 1, Prineha Narang 4, Stefan Dilhaire 1 & Philippe Lalanne 5

DOI: 10.1038/s41467-017-01802-y

Laboratoire Onde et Matière dAquitaine (LOMA), UMR 5798, CNRS-Université de Bordeaux, 33400 Talence, France. Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA. Laboratoire Charles Fabry (LCF), UMR 5298, CNRS-IOGS-Université Paris XI, Institut dOptique, 91120 Palaiseau, France. Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA. Laboratoire Photonique, Numérique et Nanosciences (LP2N), UMR 5298, CNRS-IOGS-Université de Bordeaux, Institut dOptique dAquitaine, 33400 Talence, France. Correspondence and requests for materials should be addressed to S.D. (email: stefan.dilhaire@u-bordeaux.fr) or to P.L. (email: Philippe.Lalanne@institutoptique.fr