Accelerating magnonic simulations with the pseudospectral Landau-Lifshitz equation

TL;DR

This paper introduces a pseudospectral Landau-Lifshitz model that accelerates magnonic simulations by efficiently modeling dipole interactions with a single convolution kernel, doubling computational speed for linear excitations.

Contribution

The paper demonstrates the use of the PS-LL model with a derived convolution kernel to significantly speed up magnonic simulations involving dipole interactions.

Findings

Twofold increase in simulation speed compared to full dipole calculations

Valid for linear excitations typical of magnons

Potential to accelerate inverse design in magnonics

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 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.