  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.
