Investigation of magnetostatic waves with the pseudospectral Landau-Lifshitz equation

The pseudospectral Landau-Lifshitz (PS-LL) model [1] was recently introduced to describe atomic-scale magnetic exchange interactions within a continuum model. The spectral approach reduces to the micromagnetic limit, thus enabling the inclusion of effects at long wavelengths. Here, we investigate how the PS-LL model can be used to describe magnetostatic waves. Typically, the implementation of dipole fields into such computations is an intensive and time-consuming process because of the many Fourier operations required. Despite their accuracy, thin films typically exhibit only the lowest magnetostatic mode so that its dispersion can be contained directly within the PS-LL model. We propose to use the analytically available expressions for magnetostatic waves [2] to numerically solve for dispersion relations with only one pair of Fourier transforms. This approach requires to set a specific magnetostatic wave mode with the expectation of reducing the computational cost of magnonics research, such as the exploration of nano-magnonic crystals [3].

References

[1] K. Rockwell et al., Phys. Rev. B L180404 (2024)

[2] D. D. Stancil and A. Prabhakar, Spin Waves: Theory and Applications, Springer Science and Business Media (2009)

[3] A. Roxburgh and E. Iacocca, Magnetochemistry 10, 13 (2024)