The phase-locking of multiple spin-torque nano oscillators(STNOs) is considered the primary vehicle to achieve sufficient signal quality for applications. This book highlights the resonator's design and its need for feedback for phase locking of STNOs. STNOs can act as sources of tunable microwaves after being phase-locked together. External feedback from a coplanar waveguide placed above an STNO helps ensures coherent single domain oscillations. STNOs placed within magnonic crystal cavities also demonstrate coherent oscillations. Arrays of such cavities provide a route to scale power levels from such nano-oscillators. The book presents numerical and micromagnetics to validate the design.
Author(s): C. S. Nikhil Kumar
Series: SpringerBriefs in Applied Sciences and Technology
Publisher: Springer
Year: 2022
Language: English
Pages: 104
City: Singapore
Contents
Abbreviations
Notations
List of Figures
List of Tables
1 Introduction
1.1 Magnonic Crystals
1.1.1 Magnon-Based Computing
1.1.2 Magnetoelectronics and Magnon Spintronics
1.1.3 STNO Configurations
1.1.4 STNO Device Principle
1.1.5 Mutual Synchronization of STNOs Through Electrical Coupling
1.2 Landau–Lifshitz–Gilbert–Slonczewski Equation
1.2.1 Plane Wave Method
1.2.2 Micromagnetics
1.3 Summary
References
2 Spin-Wave Excitation Patterns Generated by Spin-Torque Nano-Oscillators
2.1 Approximate Model
2.2 Micromagnetic Simulations
2.2.1 Forward Volume Spin Waves
2.2.2 Backward Volume and Surface Spin Waves
2.2.3 Multiple NC STNOs
2.3 Summary
References
3 Coherent Spin-Wave Oscillations Through External Feedback
3.1 Spintronic Oscillator with Magnetic Field Feedback
3.1.1 Quasi-Static Simulations
3.1.2 Magnetization Dynamics
3.1.3 Simulation Results
3.2 Electrical Analogy
3.3 Summary
References
4 Magnonic Spectra in 2D Antidot Magnonic Crystals with Line Defect
4.1 Plane Wave Method
4.1.1 Convergence
4.2 Eigenmodes
4.3 Micromagnetic Simulations
4.3.1 Magnonic Spectra
4.3.2 Antidot Magnonic Crystal Waveguide
4.3.3 Dispersion Analysis of an MC3 Cavity
4.4 Summary
References
5 Sustaining Spin-Wave Oscillations Through Internal Feedback
5.1 Nanocontact STNO in MC Cavity
5.1.1 Design Methodology
5.1.2 Spin-Wave Dynamics with MCC-End Fire Antenna
5.1.3 Current-Induced Oersted Field in a Micromagnetic Simulation
5.1.4 Quality Factor Calculation
5.2 Phase Locking of Nanocontact STNOs—Broad Side Antenna
5.2.1 Symmetric Array of NC STNOs
5.2.2 Asymmetric Array of NC STNOs
5.2.3 Detuning of SWs in NC STNOs in MC Cavity
5.3 Summary
References
6 Summary and Future Work
6.1 Future Work
References
Publications
