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arXiv · 1801.06662

Watching charge separation in nanoantennas by ultrafast point-projection electron microscopy

Jan Vogelsang·Germann Hergert·Dong Wang·Petra Groß·Christoph Lienau
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Abstract

Watching the motion of electrons on their natural nanometre length- and femtosecond time scales is a fundamental goal and an open challenge of contemporary ultrafast science. Optical techniques and electron microscopy currently mostly provide either ultrahigh temporal or spatial resolution, yet, microscopy techniques with combined space-time resolution need further development. Here we create an ultrafast electron source by plasmon nanofocusing on a sharp gold taper and implement this source in an ultrafast point-projection electron microscope. This source is used, in an optical pump - electron probe experiment, to study ultrafast photoemission from a nanometer-sized plasmonic antenna. We show that the real space motion of the photoemitted electrons and residual holes in the metal is probed with 20-nm spatial resolution and 25-fs time resolution. This is a step forward towards time-resolved microscopy of electronic motion in nanostructures.

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Jan Vogelsang, Germann Hergert, Dong Wang, Petra Groß, Christoph Lienau. 2018-01-20. Watching charge separation in nanoantennas by ultrafast point-projection electron microscopy. https://arxiv.org/abs/1801.06662

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