An Exact Energy Conservation Law for Magneto-Optical Nanoparticles
Optics
2026-01-16 v1 Applied Physics
Abstract
Energy conservation imposes fundamental bounds on the polarizabilities of nanoparticles (NPs). While such bounds are well established for isotropic and bianisotropic NPs, they remain unexplored for magneto-optical NPs. Here, we derive the exact energy-conservation law governing the electric and magnetic dipolar response of axially symmetric magneto-optical NPs under general illumination conditions and arbitrary external magnetic fields. Two central results follow from energy conservation: (i) purely magneto-optical scattering, where the non-magnetic polarizability vanishes, is fundamentally forbidden, and (ii) strong magneto-optical scattering regimes, in which the magneto-optical polarizability dominates, are intriguingly allowed.
Keywords
Cite
@article{arxiv.2601.10255,
title = {An Exact Energy Conservation Law for Magneto-Optical Nanoparticles},
author = {Jorge Olmos-Trigo},
journal= {arXiv preprint arXiv:2601.10255},
year = {2026}
}