Coherent perfect absorption by a single nanoparticle

The absorption of electromagnetic energy is one of the most fundamental processes that is used in many different applications, which include photovoltaics, wireless energy transfer, molecular sensing and photodetection. Increasing absorption efficiency is the key to the development of these areas. The phenomenon of total absorption consists of the absorption by the scatterer of all incident energy. Traditional approaches for constructing systems that support total absorption involve the use of extended absorbers or incident fields containing components that rapidly attenuate with distance to the absorber. In this work, we present an approach that allows the coherent total absorption phenomena in individual nanoparticles above the substrate. We demonstrate that it is possible to achieve perfect absorption using a focused beam with some given spatial distribution. This beam corresponds to a set of nanoparticle parameters for which the condition of total absorption is fulfilled. The obtained results are confirmed by full-wave simulations.