Design of an optomagnonic crystal: towards optimal magnon-photon mode matching at the microscale

TL;DR

This paper introduces an optomagnonic crystal concept that co-localizes magnon and photon modes at the microscale, aiming to enhance quantum interactions for information processing.

Contribution

It proposes a novel microscale structure design for optimal magnon-photon mode matching, demonstrating theoretical feasibility with a simple one-dimensional geometry.

Findings

Achieves optomagnonic coupling in the kHz range

Shows localization of magnon and photon modes at defects

Discusses routes to optimize coupling and reduce losses

Abstract

We put forward the concept of an optomagnonic crystal: a periodically patterned structure at the microscale based on a magnetic dielectric, which can co-localize magnon and photon modes. The co-localization in small volumes can result in large values of the photon-magnon coupling at the single quanta level, which opens perspectives for quantum information processing and quantum conversion schemes with these systems. We study theoretically a simple geometry consisting of a one-dimensional array of holes with an abrupt defect, considering the ferrimagnet Yttrium Iron Garnet (YIG) as the basis material. We show that both magnon and photon modes can be localized at the defect, and use symmetry arguments to select an optimal pair of modes in order to maximize the coupling. We show that an optomagnonic coupling in the kHz range is achievable in this geometry, and discuss possible optimization routes in order to improve both coupling strengths and optical losses.