Plasmonic nanostar photocathodes for optically-controlled directional currents

Plasmonic nanocathodes offer unique opportunities for optically driving, switching, and steering femtosecond photocurrents in nanoelectronic devices and pulsed electron sources. This paper directly characterizes multiphoton photoemission from plasmonic gold nanostars and demonstrates all-optical control over these currents. Angular control is achieved by selectively exciting different tips on single nanostars via laser frequency or linear polarization, rotating the tip-aligned directional photoemission. Classical plasmonic field simulations combined with quantum photoemission theory elucidate the mechanism for femtosecond spatiotemporal current control.

Jacob Pettine, Priscilla Choo, Fabio Medeghini, Teri W. Odom, David J. Nesbitt