title: Ultrafast Electron Emission from a Sharp Metal Nanotaper Driven by Adiabatic Nanofocusing of Surface Plasmons.
abstract: We report photoelectron emission from the apex of a sharp gold nanotaper illuminated via grating coupling at a distance of 50 μm from the emission site with few-cycle near-infrared laser pulses. We find a fifty-fold increase in electron yield over that for direct apex illumination. Spatial localization of the electron emission to a nanometer-sized region is demonstrated by point-projection microscopic imaging of a silver nanowire. Our results reveal negligible plasmon-induced electron emission from the taper shaft and thus efficient nanofocusing of few-cycle plasmon wavepackets. This novel, remotely driven emission scheme offers a particularly compact source of ultrashort electron pulses of immediate interest for miniaturized electron microscopy and diffraction schemes with ultrahigh time resolution.
authors.affiliation: †Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.|‡Center of Interface Science, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Vogelsang
authors.affiliation: †Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.|‡Center of Interface Science, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Robin
authors.affiliation: §Wigner Research Centre for Physics, 1121 Budapest, Hungary.|∥Institute of Physics, University of Pécs, 7622 Pécs, Hungary.
authors.forename: Benedek J
authors.initials: BJ
authors.lastname: Nagy
authors.affiliation: §Wigner Research Centre for Physics, 1121 Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Dombi
authors.affiliation: †Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rosenkranz
authors.affiliation: †Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Schiek
authors.affiliation: †Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.|‡Center of Interface Science, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Groß
authors.affiliation: †Institut für Physik, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.|‡Center of Interface Science, Carl von Ossietzky Universität, 26129 Oldenburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Lienau
keywords: adiabatic nanofocusing; few-cycle light pulses; nanotip electron source; point projection electron microscopy; surface plasmon polaritons; ultrafast electron microscopy