SPICE Workshop on Nanomagnetism in 3D, April 30th - May 2nd 2024
Riccardo Hertel
Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, F-67000 Strasbourg, France
Recent progress in the nanofabrication of three-dimensional magnetic nanostructures [1] has opened unprecedented opportunities to generate arbitrarily shaped artificial magnetic samples whose properties are governed by their geometric features. Suitably tailored three-dimensional magnetic samples can effectively constitute novel types of magnetic materials with unique properties. Among such artificial materials, arrays of interconnected soft-magnetic nanowires have recently emerged as a subcategory of particular interest. Such systems display features of three-dimensional artificial spin-ices, exhibiting a broad variety of magnetization states, including defect-like magnetic structures forming at the vertices where the wires intersect.
By using advanced finite-element micromagnetic simulation methods [2, 3], we investigate high-frequency magnetization oscillations in different types of magnetic nanoarchitectures consisting of interconnected soft-magnetic nanowires, ranging from buckyball-type geometries [4] to cubic arrays [5] and diamond-type artificial magnetic crystals [6]. In all cases, we find distinct resonance peaks in the absorption spectra, which can be attributed to specific geometric and micromagnetic features within the lattice. The magnetic high-frequency dynamics depends particularly sensitively on the micromagnetic structure developing at the nanowires’ intersection points. Moreover, at higher frequencies, standing-spin wave modes develop within the individual nanowires. The sensitivity of the high-frequency oscillation modes to nanoscale micromagnetic and geometric features, in combination with the high precision of modern sample fabrication methods, underlines the potential of these magnetic systems for three-dimensional magnonic applications with tunable and reconfigurable properties.
[1] A. Fernández-Pacheco, et al.: Three-Dimensional Nanomagnetism. Nature Communications, 8, 15756 (2017).[2] R. Hertel, tetmag, https://github.com/R-Hertel/tetmag (2023)
[3] M. d’Aquino and R. Hertel: Micromagnetic frequency-domain simulation methods for magnonic systems. J. Appl. Phys., 133, 033902 (2023).
[4] R. Cheenikundil, et al.: High-frequency modes in a magnetic buckyball nanoarchitecture. APL Materials, 10, 081106 (2022).
[5] R. Cheenikundil et al.: Magnetization dynamics in a three-dimensional interconnected nanowire array. arXiv:2306.00174 (2023)
[6] R. Cheenikundil et al.: Defect-Sensitive High-Frequency Modes in a Three-Dimensional Artificial Magnetic Crystal. arXiv:2312.08415 (2023)