Elastic Purcell effect

TL;DR

This paper introduces an elastic analog of the Purcell effect, demonstrating that spherical nanoparticles can act as tunable antennas to modify elastic wave emission, with potential applications in phonon control and optomechanics.

Contribution

It develops a theoretical framework for the elastic Purcell effect, including elastic parameters and mode analysis, and applies it to gold nanoparticles as GHz elastic antennas.

Findings

Shear and mixed modes yield high elastic Purcell factors.

Gold nanoparticles can serve as effective elastic GHz antennas.

Framework bridges classical and quantum phonon treatments.

Abstract

In this work, we introduce an elastic analog of the Purcell effect and show theoretically that spherical nanoparticles can serve as tunable and robust antennas for modifying the emission from localized elastic sources. This effect can be qualitatively described by introducing elastic counterparts of the familiar electromagnetic parameters: local density of elastic states, elastic Purcell factor, and effective volume of elastic modes. To illustrate our framework, we consider the example of a submicron gold sphere as a generic elastic GHz antenna and find that shear and mixed modes of low orders in such systems offer considerable elastic Purcell factors. This formalism opens pathways towards extended control over dissipation of vibrations in various optomechanical systems and contributes to closing the gap between classical and quantum-mechanical treatments of phonons localized in elastic nanoresonators.