Linear second-order IMEX-type integrator for the (eddy current) Landau–Lifshitz–Gilbert equation

Di Fratta, Giovanni and Pfeiler, Carl-Martin and Praetorius, Dirk and Ruggeri, Michele and Stiftner, Bernhard (2020) Linear second-order IMEX-type integrator for the (eddy current) Landau–Lifshitz–Gilbert equation. IMA Journal of Numerical Analysis, 40 (4). pp. 2802-2838. ISSN 0272-4979 (https://doi.org/10.1093/imanum/drz046)

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Abstract

Combining ideas from Alouges et al. (2014, A convergent and precise finite element scheme for Landau–Lifschitz–Gilbert equation. Numer. Math., 128, 407–430) and Praetorius et al. (2018, Convergence of an implicit-explicit midpoint scheme for computational micromagnetics. Comput. Math. Appl., 75, 1719–1738) we propose a numerical algorithm for the integration of the nonlinear and time-dependent Landau–Lifshitz–Gilbert (LLG) equation, which is unconditionally convergent, formally (almost) second-order in time, and requires the solution of only one linear system per time step. Only the exchange contribution is integrated implicitly in time, while the lower-order contributions like the computationally expensive stray field are treated explicitly in time. Then we extend the scheme to the coupled system of the LLG equation with the eddy current approximation of Maxwell equations. Unlike existing schemes for this system, the new integrator is unconditionally convergent, (almost) second-order in time, and requires the solution of only two linear systems per time step.

ORCID iDs

Di Fratta, Giovanni, Pfeiler, Carl-Martin, Praetorius, Dirk, Ruggeri, Michele ORCID logoORCID: https://orcid.org/0000-0001-6213-1602 and Stiftner, Bernhard;