Polarisation Control of Nanoantenna Cold Spots

Cold spots are sub-wavelength regions which might emerge near a plasmonic nanoantenna, should one or more components of some far-field illumination cancel out with scattered light. With a simplest-case demonstration using two dipolar scatterers, we show that by changing only the polarisation and amplitude of two plane waves, a unique, zero-magnitude and super sub-wavelength cold spot can be created anywhere in the space around a nanoantenna. This technique is a means for ultra-fast, remote, and non-mechanical sub-wavelength electric field manipulation.