This book briefly looks at numerical modeling and micromagnetic simulation results of magnonic crystals, which are periodically modulated magnonic devices regarded as the magnetic counterpart of photonic crystals with spin waves acting as the information carrier. Since the wavelength of the spin wave is several orders of magnitude shorter than that of electromagnetic waves of the same frequency, magnonic crystals are promising candidates for miniaturization, especially in the fields of data storage and processing. The book begins by describing the dispersion relation of dipolar spin waves in a magnonic curved waveguide, solving Walker's equation in cylindrical coordinates, and then calculating the dispersion of exchange spin waves using perturbation theory. It describes simulated nano-contact-driven spin wave excitations in a magnonic cavity, featuring a design of an antidot magnonic crystal around the nano-contact, with the frequency of the spin wave mode generated lying within the band gap of the magnonic crystal. The proposed device behaves as a SWASER―Spin Wave Amplification by the Stimulated Emission of Radiation. This book will find interest among researchers and practitioners interested in the modeling, simulation, and design of novel magnonic devices.
Author(s): C. S. Nikhil Kumar
Series: SpringerBriefs in Materials
Publisher: Springer
Year: 2023
Language: English
Pages: 88
City: Cham
Preface
References
Contents
1 Introduction
References
2 Backward Volume Spin Waves in a Rectangular Geometry
2.1 Solution to Walker's Equation
2.1.1 Dispersion Characteristics for Dipolar Spin Waves
2.1.2 Dispersion Characteristics of Exchange Spin Waves
Reference
3 Magnetostatic Waves in Magnonic Crystals: A PWM Approach
3.1 Magnetostatic Waves in 1D Magnonic Crystal
3.2 Walker's Equation in a One-Dimensional Magnonic Crystal
3.3 Dispersion Characteristics of Backward Volume Spin Waves
References
4 Field Localization in Striped Magnonic Crystal Waveguide
4.1 Geometry and Method of Analysis
4.2 Static Demagnetizing Field
4.3 Spin Wave Magnonic Band
4.4 Spin Wave Localizations in Striped Magnonic Waveguide
4.5 Convergence
4.6 Conclusion
References
5 Walker's Solution for Curved Magnonic Waveguide and Resonant Modes in Magnonic Ring
5.1 Spin Wave Dispersion for Curved Magnonic Waveguide
5.1.1 Geometry and Analysis
5.1.2 Dispersion Relation of Curved Magnonic Waveguide
5.1.3 Validations
5.1.4 Modes in a Magnonic Ring
5.2 Conclusion
References
6 Nanocontact-Driven Spin Wave Excitations in Magnonic Cavity
6.1 Introduction
6.2 Micromagnetic Simulations
6.3 Method of Calculation
6.3.1 Band Structure of Antidot MC
6.3.2 Spin Wave Injection on Py Film Using an Array of Nanocontacts
6.3.3 Fabry-Perot Model
6.3.4 SW Spectra
6.3.5 Quality Factor Calculation
6.4 Conclusion
References
7 Magnetic Field Feedback Oscillator: A Micromagnetic Study
7.1 Introduction
7.2 Feedback Oscillator with Magnetic Field Feedback: A Closed Loop System Study
7.2.1 Micromagnetic Simulation Without Magnetic Field Feedback
7.2.2 Free Layer Model
7.2.3 Free Layer Hysteresis Loops
7.2.4 Ferromagnetic Resonance Frequency Versus Applied Field
7.2.5 Current Dependence on Resonance Frequency
7.2.6 Spintronic Oscillators with Magnetic Field Feedback
7.2.7 Spin Wave Dynamics with Magnetic Field Feedback
7.2.8 Spin Wave Dynamics at 300 K
7.2.9 Spin Wave Spectra with Different Delays
7.3 Conclusion
References
Appendix Appendix
A.1 Derivation of Permeability Tensor
A.2 General Solution of Walker's Equation
A.3 Micromagnetic Simulation Script
Reference
