Longitudinal Angular Momentum in Magneto-Mie Scattering: Quantum Vacuum Correction to the Einstein-De Haas effect

TL;DR

This paper explores how quantum vacuum effects influence angular momentum in a dielectric sphere under magnetic fields, revealing a quantum correction to the classical Einstein-De Haas effect through electromagnetic vortex dynamics.

Contribution

It introduces the concept of quantum vacuum-induced angular momentum in Mie spheres and quantifies its correction to the Einstein-De Haas effect.

Findings

Quantum vacuum creates a vortex of the Poynting vector within the sphere.

Longitudinal electric modes are excited on the sphere's surface and inside due to the Faraday effect.

Quantum vacuum correction can significantly modify the classical Einstein-De Haas effect.

Abstract

This work investigates the angular momentum of the electromagnetic quantum vacuum residing in a dielectric Mie sphere subject to the Faraday effect. Longitudinal electric modes are excited on its surface and are also created inside the sphere by the Faraday effect.The electromagnetic quantum vacuum creates a vortex of the Poynting vector that varies as $1/r$ to the center of the sphere and is associated with longitudinal angular momentum, connected to the vector potential $\mathbf{A}(\mathbf{r},t)$. It emerges as a non-negligible quantum vacuum correction to the classical (diamagnetic) Einstein-De Haas effect in which an applied external magnetic field - via its action on microscopic magnetism - enforces macroscopic rotation.