Interaction of Mechanical Oscillators Mediated by the Exchange of Virtual Photon Pairs
Journal article, 2019

Two close parallel mirrors attract due to a small force (Casimir effect) originating from the quantum vacuum fluctuations of the electromagnetic field. These vacuum fluctuations can also induce motional forces exerted upon one mirror when the other one moves. Here, we consider an optomechanical system consisting of two vibrating mirrors constituting an optical resonator. We find that motional forces can determine noticeable coupling rates between the two spatially separated vibrating mirrors. We show that, by tuning the two mechanical oscillators into resonance, energy is exchanged between them at the quantum level. This coherent motional coupling is enabled by the exchange of virtual photon pairs, originating from the dynamical Casimir effect. The process proposed here shows that the electromagnetic quantum vacuum is able to transfer mechanical energy somewhat like an ordinary fluid. We show that this system can also operate as a mechanical parametric down-converter even at very weak excitations. These results demonstrate that vacuum-induced motional forces open up new possibilities for the development of optomechanical quantum technologies.

Electromagnetic fields


Oscillators (mechanical)



Omar Di Stefano


Alessio Settineri

Universita degli Studi di Messina

Vincenzo MacRí


Alessandro Ridolfo

Universita degli Studi di Catania


Roberto Stassi


Anton Frisk Kockum


Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Salvatore Savasta

Universita degli Studi di Messina


Franco Nori


University of Michigan

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 122 3 030402

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Theoretical Chemistry



More information

Latest update