Περίληψη:
We study magnon-mediated optical transitions in micrometer-sized axially
symmetric yttrium iron garnet (YIG) particles, which act as optomagnonic
cavities, by means of electromagnetic calculations, treating the
magneto-optical coupling to first order in perturbation theory, in the
framework of a fully dynamic approach. Such particles with engineered
shape anisotropy exhibit high-quality-factor Mie resonances in the
infrared part of the spectrum, with a separation of few gigahertz, which
matches the typical frequencies of magnons. This allows for optical
transitions mediated by spin waves, while the micrometer volume favors
stronger overlap between the optical modes and the precessing
magnetization. Our results predict that photon-magnon coupling strengths
of tens of kilohertz could be realized with cylindrical or spheroidal
particles, since mainly the reduced volume, but also shape anisotropy,
can lead to strong, up to four orders of magnitude, enhancement of the
coupling strengths compared to submillimeter YIG spheres.
Συγγραφείς:
Almpanis, E.
Papanikolaou, N.
Stefanou, N.