Multifunctional operation of the double-layer ferromagnetic structure coupled by a rectangular nanoresonator

Abstract

The use of spin waves as a signal carrier requires developing the functional elements allowing for multiplexing and demultiplexing information coded at different wavelengths. For this purpose, we propose a system of thin ferromagnetic layers dynamically coupled by a rectangular ferromagnetic resonator. We show that single and double, clockwise and counterclockwise, circulating modes of the resonator offer a wide possibility of control of propagating waves. Particularly, at frequency related to the double-clockwise circulating spin-wave mode of the resonator, the spin wave excited in one layer is transferred to the second one where it propagates in the backward direction. Interestingly, the wave excited in the second layer propagates in the forward direction only in that layer. This demonstrates add-drop filtering and circulator functionality. Thus, the proposed system can become an important part of future magnonic technology for signal routing.

A modal approach to modelling spin wave scattering

“…We use the proposed method to study the transmission and reflection of spin waves on a ferromagnetic stripe coupled with a ferromagnetic film. This system can be considered as a basic building block of magnonic circuits possessing various functionalities [13,14,16,[34][35][36][37][38][39]. We elucidate the important role played by pairs of modes with contrasting group velocities supported by the bilayer formed by the film and the stripe.…”