Near-field energy transfer between nanoparticles modulated by coupled multipolar modes

The near-field energy transfer between dielectric nanoparticles by considering the full coupling between all the thermal electric fields is studied theoretically for the case of a dimer and a trimer. We show that coupled modes between nanoparticles open channels through which energy may be transferred, increasing the power exchanged more than one order of magnitude as compared with existing models. We discuss how the contribution from coupled modes changes as parameters of the system are varied for the case of a two- and three-particle system. It is done by developing a spectral representation formalism for the near field, where fluctuating multipolar moments are fully incorporated, allowing identification of the contribution of energy transfer of each coupled mode. This information can be used to understand and control the energy flux among nanoparticles.