Optical-field-controlled photoemission from plasmonic nanoparticles

At high intensities, light-matter interactions are controlled by the electric field of the exciting light. For instance, when an intense laser pulse interacts with an atomic gas, individual cycles of the incident electric field ionize gas atoms and steer the resulting attosecond-duration electrical wavepackets1,2. Such field-controlled light-matter interactions form the basis of attosecond science and have recently expanded from gases to solid-state nanostructures3-18. Here, we extend these field-controlled interactions to metallic nanoparticles supporting localized surface plasmon resonances. We demonstrate strong-field, carrier-envelope-phase-sensitive photoemission from arrays of tailored metallic nanoparticles, and we show the influence of the nanoparticle geometry and the plasmon resonance on the phase-sensitive response. Additionally, from a technological standpoint, we push strong-field light-matter interactions to the chip scale. We integrate our plasmonic nanoparticles and experimental geometry in compact, microoptoelectronic devices that operate out of vacuum and under ambient conditions.