Green Tensor Analysis of Lattice Resonances in Periodic Arrays of Nanoparticles

TL;DR

This paper demonstrates that lattice resonances in periodic arrays of metallic nanoparticles significantly enhance long-range electromagnetic coupling between dipole emitters, with potential applications in energy transfer and quantum information.

Contribution

The study introduces a Green tensor analysis of lattice resonances, revealing their role in mediating long-range emitter coupling in nanoparticle arrays, which was not previously characterized.

Findings

Green tensor is larger and decays more slowly at lattice resonances

Lattice resonances enable efficient long-range coupling between dipole emitters

Arrays of nanostructures can be used for energy transfer and quantum information

Abstract

When arranged in a periodic geometry, arrays of metallic nanostructures are capable of supporting collective modes known as lattice resonances. These modes, which originate from the coherent multiple scattering between the elements of the array, give rise to very strong and spectrally narrow optical responses. Here, we show that, thanks to their collective nature, the lattice resonances of a periodic array of metallic nanoparticles can mediate an efficient long-range coupling between dipole emitters placed near the array. Specifically, using a coupled dipole approach, we calculate the Green tensor of the array connecting two points and analyze its spectral and spatial characteristics. This quantity represents the electromagnetic field produced by the array at a given position when excited by a unit dipole emitter located at another one. We find that, when a lattice resonance is excited, the Green tensor is significantly larger and decays more slowly with distance than the Green tensor of vacuum. Therefore, in addition to advancing the fundamental understanding of lattice resonances, our results show that periodic arrays of nanostructures are capable of enhancing the long-range coupling between collections of dipole emitters, which makes them a promising platform for applications such as nanoscale energy transfer and quantum information processing.