Original Article

, Volume: 11( 6) DOI: 10.37532/2320-6756.2023.11(6).356

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Tailoring Geometries and Magnetic Configurations in Magnetochiral Nanotubes for Enhanced Spin-Wave Properties: Towards Energy-Efficient, High-Density 3D

*Correspondence:

Thiago M. Nóbrega Universidade Paulista, São Paulo, Brazil, E-mail: thiagomnobrega@gmail.com

Abstract

The development of energy-efficient, high-density three-dimensional (3D) magnonic devices has garnered significant interest due to their potential for revolutionizing information processing and storage technologies. Building upon recent findings on spin-wave modes in magneto chiral nanotubes with axial and circumferential magnetization, this study investigates the effects of tailored geometries and magnetic configurations on the spin-wave properties of these nanostructures. By employing advanced simulation techniques, experimental methods, and theoretical analysis, we explore the interplay between geometry, magnetization, and spin-wave dynamics in magneto chiral nanotubes. Our results reveal that specific combinations of geometrical parameters and magnetic configurations lead to enhanced spin-wave properties, paving the way for the design of novel 3D magnonic devices with improved performance and energy efficiency. Furthermore, we demonstrate the potential of these optimized magneto chiral nanotubes for various applications, including logic nano elements and vertical through-chip via in 3D magnonic device architectures. This study not only advances our understanding of spin-wave dynamics in magnetochiral nanotubes but also provides a foundation for the development of next-generation magnonic devices.

Keywords

Magneto chiral; Nanostructures

Introduction

Manganic, the study of spin waves and their quanta (magnons), has emerged as a promising field for the development of novel information processing and storage technologies. The utilization of spin waves in manganic devices offers several advantages over conventional charge-based electronics, including lower energy consumption, reduced heat generation, and the potential for higher integration density [1-3]. In recent years, three-dimensional (3D) magnetic nanostructures have attracted significant attention as building blocks for advanced manganic devices, owing to their unique properties and potential for high-density integration [3-6].

Magneto chiral nanotubes, which are prototypical 3D nano magnetic structures, exhibit versatile properties that depend on their geometrical parameters (e.g., length, inner and outer radius) and magnetic configurations (e.g., axial, helical, or vortex-like) [7]. The curvature-induced magneto chiral field, originating from dipole-dipole interaction, can induce non-reciprocal spin-wave dispersion relations in cylindrical nanotubes with nano metric radii and circular cross-sections [7]. Previous studies have investigated spin-wave modes in nanotubes with hexagonal cross-sections, revealing the potential of these structures for various manganic applications [7].

The recent work by Giordano et al. (2023) provided valuable insights into the spin-wave modes in magneto chiral nanotubes with axial and circumferential magnetization, uncovering the unusual nature of confined modes and the curvature-induced magneto chiral effect. Building upon these findings, the present study aims to explore the potential of magneto chiral nanotubes with tailored geometries and magnetic configurations for energy-efficient, high-density 3D manganic devices.

In this paper, we investigate the effects of varying geometries and magnetic configurations of magneto chiral nanotubes on their spin-wave properties. We employ a combination of advanced simulation techniques, experimental methods, and theoretical analysis to examine the interplay between geometry, magnetization, and spin-wave dynamics in these novel nanostructures. Our findings contribute to the understanding of spin-wave properties in magneto chiral nanotubes and pave the way for the development of innovative manganic devices with improved performance and energy efficiency.

In the present work, we tried to find the solutions for the said isolated system with trajectories of the bodies, which differ from geodesic lines. Evidently, both classical mechanics and general relativity theory give a negative answer to this question [2-4]. Therefore, further consideration is based on the principles of the Special Relativity Theory (SRT).

Materials and Methods

Sample Preparation and Characterization

Magneto chiral nanotubes were synthesized using a Plasma-Enhanced Atomic Layer Deposition (PEALD) process. The nanotubes consist of a 22 nm-thick Permalloy (Py) shell covering a hexagonal GaAs nanowire core and a 5 nm thin spacer layer of Al2O3, which separates the Py and GaAs layers. The samples were characterized using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) to determine their geometrical parameters, such as inner and outer radii, and to confirm the uniformity of the Py shell.

Experimental Setup and Brillouin Light Scattering Microscopy

The magneto chiral nanotubes were positioned in the gap of a Coplanar Waveguide (CPW) for spin-wave excitation and detection. A microwave-frequency current was applied to the CPW, generating a dynamic magnetic field that excited spin precession in the adjacent ferromagnetic nanotube. Spin-processional motion was detected using Brillouin Light Scattering (BLS) microscopy at room temperature, with a monochromatic blue laser focused on the sample’s top surface and in elastically scattered light collected in back-reflection geometry.

Micro magnetic Simulations

Micro magnetic simulations were performed using the Object-Oriented Micro Magnetic Framework (OOMMF), with material parameters and simulation settings provided in the Supplemental Material [8, 9]. The simulations were used to calculate Eigen frequencies extracted from Power Spectral Density (PSD) spectra and to visualize spin-processional motion. The simulated results were compared with experimental BLS spectra to identify and analyze the spin-wave modes in the magneto chiral nanotubes.

Data Analysis

The experimental and simulated data was analyzed to identify the spin wave modes and their dependence on the geometrical parameters and magnetic configurations of the magneto chiral nanotubes. The spin-wave properties, such as dispersion relations and mode profiles, were extracted and compared with theoretical predictions and previous studies.

The effects of varying geometries and magnetic configurations on the spin-wave properties were investigated to identify optimal designs for energy-efficient, high-density 3D manganic devices.

Results

Spin-Wave modes in magneto chiral nanotubes

Our experimental BLS spectra and micro magnetic simulations revealed a variety of spin-wave modes in magneto chiral nanotubes with different geometries and magnetic configurations. We observed distinct mode profiles and dispersion relations, which were consistent with the simulated results, indicating the presence of confined modes and curvature-induced magneto chiral effects.

Effects of geometrical parameters and magnetic configurations

By systematically varying the geometrical parameters and magnetic configurations of the magneto chiral nanotubes, we identified specific combinations that led to enhanced spin-wave properties. These optimized designs exhibited improved mode confinement, reduced mode overlap, and increased mode separation, which are crucial for the development of high-performance 3D magnonic devices.

Comparison with theoretical predictions and previous studies

Our results were in good agreement with theoretical predictions and previous studies on spin-wave modes in magneto chiral nanotubes. The observed spin-wave properties, such as dispersion relations and mode profiles, were consistent with the curvatureinduced magneto chiral effect and the unusual nature of confined modes reported in the literature.

Spin-Wave properties in optimized magneto chiral nanotubes

The optimized magneto chiral nanotubes exhibited promising spin-wave properties for various manganic applications, including logic nano elements and vertical through-chip via in 3D manganic device architectures. The enhanced spin wave properties in these optimized designs could potentially lead to improved performance and energy efficiency in next-generation manganic devices.

Discussion

Interpretation of spin-wave modes and magneto chiral effects

Our study revealed a variety of spin-wave modes in magneto chiral nanotubes with different geometries and magnetic configurations. The observed modes were consistent with the simulated results, indicating the presence of confined modes and curvature-induced magneto chiral effects. These findings provide valuable insights into the spin-wave dynamics in magneto chiral nanotubes and their potential for energy-efficient, high-density 3D manganic devices.

Optimal geometries and magnetic configurations for enhanced spin-wave properties

By systematically varying the geometrical parameters and magnetic configurations of the magneto chiral nanotubes, we identified specific combinations that led to enhanced spin-wave properties. These optimized designs could potentially improve the performance and energy efficiency of next-generation manganic devices. Further research could explore a wider range of geometries and magnetic configurations to identify additional optimal designs for various manganic applications.

Comparison with previous studies and theoretical predictions

Our results were in good agreement with theoretical predictions and previous studies on spin-wave modes in magneto chiral nanotubes. The observed spin-wave properties, such as dispersion relations and mode profiles, were consistent with the curvatureinduced magneto chiral effect and the unusual nature of confined modes reported in the literature. This consistency validates our experimental and simulation methods and supports the potential of magneto chiral nanotubes for advanced manganic applications.

Implications for the development of 3D manganic devices

The enhanced spin-wave properties observed in optimized magneto chiral nanotubes could pave the way for the development of novel 3D manganic devices with improved performance and energy efficiency. Potential applications include logic nano elements and vertical through-chip via in 3D manganic device architectures. Our findings contribute to the understanding of spin-wave dynamics in magneto chiral nanotubes and provide a foundation for the development of next-generation manganic devices.

Conclusion

In this study, we investigated the effects of tailored geometries and magnetic configurations on the spin-wave properties of magneto chiral nanotubes. By employing advanced simulation techniques, experimental methods, and theoretical analysis, we explored the interplay between geometry, magnetization, and spin-wave dynamics in these novel nanostructures. Our findings revealed a variety of spin-wave modes consistent with the presence of confined modes and curvature induced magneto chiral effects. We identified specific combinations of geometrical parameters and magnetic configurations that led to enhanced spin-wave properties, which are crucial for the development of high-performance 3D manganic devices. The optimized magneto chiral nanotubes exhibited promising spin-wave properties for various manganic applications, including logic nano elements and vertical through-chip via in 3D manganic device architectures.

Our results not only advance our understanding of spin-wave dynamics in magneto chiral nanotubes but also provide a foundation for the development of next-generation manganic devices with improved performance and energy efficiency. However, it is important to acknowledge the limitations of our study, such as the finite penetration depth of the laser in the BLS experiments and the homogeneous magnetic pulse in the micro magnetic simulations. Future research could explore a wider range of geometries and magnetic configurations, as well as address these limitations to further optimize the design of magneto chiral nanotubes for advanced manganic applications.

Acknowledgments

Special thanks go to the staff at the microscopy facilities for their help with sample characterization and imaging. We appreciate the efforts of those who contributed to the development and maintenance of the simulation tools and software used in this study. Finally, we acknowledge the reviewers for their constructive feedback and suggestions, which helped improve the quality of our manuscript.

Supplementary Material

Material parameters for micro magnetic simulations

The material parameters used in the micro magnetic simulations for the Permalloy (Py) shell of the magneto chiral nanotubes are as follows:

•Saturation magnetization (Ms): 800 kAm^-2

•Exchange stiffness constant (Aex): 13 pJm^-3

•Gilbert damping constant: 0.014

•Anisotropy constant (K): 0 (assuming negligible magneto crystalline anisotropy)

Simulation settings for OOMMF

The Object-Oriented Micro Magnetic Framework (OOMMF) simulations were performed using the following settings:

•Cell size: 2 nm × 2 nm × 2 nm (chosen based on the convergence test)

•Time step: 1 ps

•External magnetic field: varied to achieve different magnetic configurations

•Simulation duration: 10 ns

Additional experimental data

Additional experimental BLS spectra and SEM images of the magneto chiral nanotubes with different geometries and magnetic configurations are provided in this section. These data support the main findings of the study and provide further evidence for the observed spin-wave modes and their dependence on the geometrical parameters and magnetic configurations.

Theoretical calculations

Detailed theoretical calculations for the spin-wave dispersion relations and mode profiles in magneto chiral nanotubes are provided in this section. These calculations are based on the analytical model developed by [8] and are used to compare with the experimental and simulated results. The agreement between the theoretical predictions and the observed spin-wave properties validates our experimental and simulation methods and supports the potential of magneto chiral nanotubes for advanced manganic applications.

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