Engineered Magnetization Dynamics of Magnonic Nanograting Filters

Rawana Yagan,Ferhat Katmis,Mehmet C Onbaşlı

doi:10.3390/magnetochemistry7060081

Rawana Yagan, Ferhat Katmis + Show 1 more

Open Access

https://doi.org/10.3390/magnetochemistry7060081

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Abstract

Magnonic crystals and gratings could enable tunable spin-wave filters, logic, and frequency multiplier devices. Using micromagnetic models, we investigate the effect of nanowire damping, excitation frequency and geometry on the spin wave modes, spatial and temporal transmission profiles for a finite patterned nanograting under external direct current (DC) and radio frequency (RF) magnetic fields. Studying the effect of Gilbert damping constant on the temporal and spectral responses shows that low-damping leads to longer mode propagation lengths due to low-loss and high-frequency excitations are also transmitted with high intensity. When the nanowire is excited with stronger external RF fields, higher frequency spin wave modes are transmitted with higher intensities. Changing the nanowire grating width, pitch and its number of periods helps shift the transmitted frequencies over super high-frequency (SHF) range, spans S, C, X, Ku, and K bands (3–30 GHz). Our design could enable spin-wave frequency multipliers, selective filtering, excitation, and suppression in magnetic nanowires.

Highlights

Spin signal processing such as filtering, frequency multiplication, and excitation in GHz bands could enable on-chip integration for compact microwave data communication, data storage, as well as information transfer in ferromagnetic waveguides [1,2]
We look at the effect of increasing the excitation frequency of an radio frequency (RF) signal applied to the nanowire, which contributes to the excitation of the eigenmode in the structure
We include the results of varying material properties; Gilbert damping coefficient (α) and Ms, varying RF signal excitation frequency and the change in the width modulated grating geometry, on the output magnetization temporal profiles and their steady-state spectra of the nanowire filter

Summary

Introduction

Spin signal processing such as filtering, frequency multiplication, and excitation in GHz bands could enable on-chip integration for compact microwave data communication, data storage, as well as information transfer in ferromagnetic waveguides [1,2]. Many of these functionalities could be established within the same physically defined structure via magnonic crystals (MCs) on the nanoscale. MC are spin waveguides that can be rationally designed [3] or dynamically reconfigured [4] for functional spin transfer by engineering the voltage or magnetic field induced spin-wave dispersion dynamics. Besides that spatial periodic variation of saturation magnetization, alternating nanostrips, filters, and phase shifters were investigated with different material classes [8,13,14,15,16], where Y3 Fe5 O12 (YIG) and permalloy were the common types for MC

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