Controllable Non-reciprocity in Multi-sphere Loaded Chiral Resonator

TL;DR

This paper demonstrates a controllable non-reciprocal microwave resonator using multiple yttrium iron garnet spheres in a chiral cavity, with potential applications in RF isolators and scalable information systems.

Contribution

It introduces a novel chiral resonator loaded with multiple spheres that achieves tunable non-reciprocity, supported by a theoretical model linking phase behavior to non-reciprocal effects.

Findings

Achieved an absolute isolation ratio of 46 dB.

Developed a theoretical model based on input-output formalism.

Showed potential for programmable RF isolators and circulators.

Abstract

Cavity magnonics explores the hybridization of photons and magnons within microwave resonators. One of the hallmarks of these systems is their ability to exhibit non-reciprocity, which is a key feature for radio frequency (RF) applications. One way to control non-reciprocal behaviors in cavity magnonics is the design of chiral cavities that allow selective coupling between photons and magnons depending on their polarization. However, a built-in chiral platform to harness and control non-reciprocity remains to be achieved. Here, we experimentally demonstrate controllable non-reciprocity (with an absolute isolation ratio reaching 46 dB) in a chiral resonator loaded with multiple yttrium iron garnet spheres. We develop a theoretical model of the S-parameters based on input-output formalism which highlights the links between the phases occurring in the system and its non-reciprocal behavior. Controllable non-reciprocity in cavity magnonics could enable the development of programmable isolators, circulators, and RF switches with improved performance. Such developments could pave the way toward more versatile and scalable information processing systems.