Impact of DC bias on weak optical-field-driven electron emission in nano-vacuum-gap detectors

In this work, we investigate multiphoton and optical field tunneling emission from metallic surfaces with nanoscale vacuum gaps. Using time-dependent Schrödinger equation (TDSE) simulations, find that the properties of emitted photocurrent in such systems can be greatly altered by application only a few-volt direct current (DC) bias. We when coupled expected plasmonic enhancements within nanometer-scale gaps, DC bias significantly reduces threshold for transition to optical-field-driven metal surface, could sufficiently enhance photocurrents, make it feasible electronically tag fJ ultrafast pulses at room temperature. Given petahertz-scale instantaneous response low effective capacitance thin-film nanoantenna devices enables < 1 f mathvariant="normal">s time, detectors exploit bias-enhanced surface gaps prove useful communication, petahertz electronics, optical-field-resolved metrology.