Tuneable plasmonics enabled by capillary oscillations of liquid-metal nanodroplets

Abstract

Plasmonics allows manipulating light at the nanoscale, but has limitations due to the static nature of nanostructures and lack of tuneability. We propose and theoretically analyse a room-temperature liquid-metal nanodroplet that changes its shape, and therefore tunes the plasmon resonance frequency, due to capillary oscillations. We show the possibility to tune the capillary oscillation frequency of the nanodroplet and to drive the oscillations electrically or mechanically. Employed as a tuneable nanoantenna, the nanodroplet may find applications in sensors, imaging, microscopy, and medicine.