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Deep learning statistical defect models on magnetic material dynamic and static properties
Authors:
C. Eagan,
M. Copus,
E. Iacocca
Abstract:
The modeling of realistic magnetic materials requires the inclusion of defects. Based on the pseudospectral Landau-Lifshitz description of magnetisation dynamics, we propose a statistical model that takes into account defects, specifically vacancies. This statistical model can be integrated with deep learning techniques that correlate defect thresholds with relevant physical observables. We develo…
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The modeling of realistic magnetic materials requires the inclusion of defects. Based on the pseudospectral Landau-Lifshitz description of magnetisation dynamics, we propose a statistical model that takes into account defects, specifically vacancies. This statistical model can be integrated with deep learning techniques that correlate defect thresholds with relevant physical observables. We develop a convolutional neural network and a physics-informed neural network combined with theory of functional connections to predict the dispersion relation given defect parameters and physical constraints. A two-branch convolutional neural network is developed to predict domain-wall widths depending on defects threshold, taking into account the spatial profile and domain-wall width separately to achieve a prediction. The proposed physics-informed approaches leverage deep-learning and achieve statistical predictions measured in physical units. This is a stepping stone towards the discovery of new materials and the determination of minimal defect thresholds required for desired dynamics, states, or topological textures.
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Submitted 10 March, 2026;
originally announced March 2026.
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Accelerating magnonic simulations with the pseudospectral Landau-Lifshitz equation
Authors:
A. Roxburgh,
M. Copus,
E. Iacocca
Abstract:
The pseudospectral Landau-Lifshitz (PS-LL) model can describe atomic-scale magnetic exchange interactions within a continuum framework. This is achieved by employing a convolution kernel that models the nonlocal interaction in a grid-independent manner. Even though the PS-LL was originally introduced to address atomic exchange, any nonlocal kernel can be modeled. In the field of magnonics, the dip…
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The pseudospectral Landau-Lifshitz (PS-LL) model can describe atomic-scale magnetic exchange interactions within a continuum framework. This is achieved by employing a convolution kernel that models the nonlocal interaction in a grid-independent manner. Even though the PS-LL was originally introduced to address atomic exchange, any nonlocal kernel can be modeled. In the field of magnonics, the dipole field is fundamental to describe the dispersion relation of magnons, the quasiparticle representation of angular momentum. Because dipole-dipole interactions are long-range, numerical approaches typically rely on convolutions. Here, we demonstrate that the PS-LL model can be used to perform magnonic simulations with a single convolution kernel derived from analytical solutions. We demonstrate a twofold increase in computational speed compared with the full dipole calculation. This approach is valid insofar as the excitations are linear, which is typically the case for magnons. Our results have the potential to accelerate magnonic research, particularly for the inverse design method, where several simulations must be performed to achieve the desired outcome.
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Submitted 25 July, 2025;
originally announced July 2025.
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Dynamic annihilation pathways of magnetic skyrmions
Authors:
Matthew Copus,
Ezio Iacocca
Abstract:
The investigation of magnetic solitons often relies on numerical modeling to determine key features such as stability, annihilation, nucleation, and motion. However, as soliton sizes approach atomic length scales, the accuracy of these predictions become increasingly sensitive to the details of the numerical model. Here, we study the annihilation of two-dimensional magnetic skyrmions using a pseud…
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The investigation of magnetic solitons often relies on numerical modeling to determine key features such as stability, annihilation, nucleation, and motion. However, as soliton sizes approach atomic length scales, the accuracy of these predictions become increasingly sensitive to the details of the numerical model. Here, we study the annihilation of two-dimensional magnetic skyrmions using a pseudospectral approach and compare its performance to that of conventional micromagnetic simulations. A central distinction between the models lies in their treatment of the exchange interaction, which governs the magnon dispersion relation and plays a crucial role to balance the uniaxial anisotropy to stabilise skyrmions. We demonstrate that both the choice of model and spatial discretisation significantly influence the skyrmion dynamics and the magnetic field required for annihilation. The pseudospectral model provides a consistent description across length scales and captures complex behaviours such as skyrmion breathing on its path to annihilation. Our results have direct implications in the state-of-the-art modeling of skyrmions and other two-dimensional textures and will impact the modeling of three-dimensional textures such as hopfions. More broadly, our approach will contribute to the development seamless multiscale model and optimization machine learning approaches for material discovery.
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Submitted 21 November, 2025; v1 submitted 18 July, 2025;
originally announced July 2025.
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Spin-wave frequency combs
Authors:
Tobias Hula,
Katrin Schultheiss,
Francisco José Trindade Goncalves,
Lukas Körber,
Mauricio Bejarano,
Matthew Copus,
Luis Flacke,
Lukas Liensberger,
Aleksandr Buzdakov,
Attila Kákay,
Mathias Weiler,
Robert Camley,
Jürgen Fassbender,
Helmut Schultheiß
Abstract:
We experimentally demonstrate the generation of spin-wave frequency combs based on the nonlinear interaction of propagating spin waves in a microstructured waveguide. By means of time and space-resolved Brillouin light scattering spectroscopy, we show that the simultaneous excitation of spin waves with different frequencies leads to a cascade of four-magnon scattering events which ultimately resul…
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We experimentally demonstrate the generation of spin-wave frequency combs based on the nonlinear interaction of propagating spin waves in a microstructured waveguide. By means of time and space-resolved Brillouin light scattering spectroscopy, we show that the simultaneous excitation of spin waves with different frequencies leads to a cascade of four-magnon scattering events which ultimately results in well-defined frequency combs. Their spectral weight can be tuned by the choice of amplitude and frequency of the input signals. Furthermore, we introduce a model for stimulated four-magnon scattering which describes the formation of spin-wave frequency combs in the frequency and time domain.
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Submitted 1 March, 2022; v1 submitted 23 April, 2021;
originally announced April 2021.