Optical magnetic dipole levitation using a plasmonic surface

TL;DR

This paper demonstrates optical levitation of magnetic dipoles over various realistic materials, including bulk metals, simplifying fabrication and enabling new nanomechanical device applications.

Contribution

It introduces a method for levitating magnetic dipoles using common materials, overcoming previous fabrication challenges associated with specialized surfaces.

Findings

Levitation is effective over a wide range of materials including bulk metals.

The levitation force is independent of surface losses.

Proposed experiment involves a core-shell nanoparticle near a gold substrate.

Abstract

Optically-induced magnetic resonances in non-magnetic media have unlocked magnetic light-matter interactions and led to new technologies in many research fields. Previous proposals for the levitation of nanoscale particles without structured illumination have worked on the basis of epsilon-near-zero surfaces or anisotropic materials but these carry with them significant fabrication difficulties. We report the optical levitation of a magnetic dipole over a wide range of realistic materials, including bulk metals, thereby relieving these difficulties. The repulsion is independent of surface losses and we propose an experiment to detect this force which consists of a core-shell nanoparticle, exhibiting a magnetic resonance, in close proximity to a gold substrate under plane wave illumination. We anticipate the use of this phenomenon in new nanomechanical devices.