On orbital angular momentum conservation in Brillouin light scattering within a ferromagnetic sphere
| Autor: | Arnaud Gloppe, Koji Usami, Yasunobu Nakamura, Alto Osada |
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| Rok vydání: | 2017 |
| Předmět: |
Angular momentum
Photon General Physics and Astronomy Physics::Optics FOS: Physical sciences 02 engineering and technology 01 natural sciences Light scattering 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 010306 general physics Spin (physics) Physics Quantum Physics Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Scattering 021001 nanoscience & nanotechnology Brillouin zone Ferromagnetism Condensed Matter::Strongly Correlated Electrons 0210 nano-technology Quantum Physics (quant-ph) Optical vortex Physics - Optics Optics (physics.optics) |
| DOI: | 10.48550/arxiv.1711.09321 |
| Popis: | Magnetostatic modes supported by a ferromagnetic sphere have been known as the Walker modes, each of which possesses an orbital angular momentum as well as a spin angular momentum along a static magnetic field. The Walker modes with non-zero orbital angular momenta exhibit topologically non-trivial spin textures, which we call \textit{magnetic quasi-vortices}. Photons in optical whispering gallery modes supported by a dielectric sphere possess orbital and spin angular momenta forming \textit{optical vortices}. Within a ferromagnetic, as well as dielectric, sphere, two forms of vortices interact in the process of Brillouin light scattering. We argue that in the scattering there is a selection rule that dictates the exchange of orbital angular momenta between the vortices. The selection rule is shown to be responsible for the experimentally observed nonreciprocal Brillouin light scattering. Comment: 7 pages, 4 figures |
| Databáze: | OpenAIRE |
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