Year: 2020
Type: article
Abstract: Plasmonic nanocathodes offer unique opportunities for optically driving, switching, and steering femtosecond photocurrents in nanoelectronic devices and pulsed electron sources. However, angular photocurrent distributions in nanoplasmonic systems remain poorly understood and are therefore difficult to anticipate and control. Here, we provide a direct momentum-space characterization of multiphoton photoemission from plasmonic gold nanostars and demonstrate all-optical control over these currents. Versatile angular control is achieved by selectively exciting different tips on single nanostars via laser frequency or linear polarization, thereby rotating the tip-aligned directional photoemission as observed with angle-resolved 2D velocity mapping and 3D reconstruction. Classical plasmonic field simulations combined with quantum photoemission theory elucidate the role of surface-mediated nonlinear excitation for plasmonic field enhancements highly concentrated at the sharp tips (Rtip = 3.4 nm). We thus establish a simple mechanism for femtosecond spatiotemporal current control in designer nanosystems.
Source: Nature Communications
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,380
Awards: TAS::57 3600::TAS "STATE-RESOLVED THERMAL/HYPERTHERMAL COLLISIONAL DYNAMICS OF ATMOSPHERIC SPECIES DATED 17 MAR 2014, REVISED 15 JAN 2015", G1523888516, Correlative Tools for in Situ Analysis of Single Nanoparticles and their Ligands, JILA PFC: Measurement, Manipulation, and Meaning at the Quantum Frontier, State-Resolved Spectroscopy and Dynamics of Chemical Transients, G595102867, G6296042873, G759554275
OpenAlex ID: W3010652009