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arXiv · 2605.05129

BDF2-type integrator for Landau-Lifshitz-Gilbert equation in micromagnetics: a-priori error estimates

Michele Aldé·Dirk Praetorius·Michael Feischl
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Abstract

We consider the Landau-Lifshitz-Gilbert equation (LLG), which models time-dependent micromagnetic phenomena. We analyze a fully discrete scheme that combines first-order finite elements in space with a BDF2 method in time. The method requires the solution of only one linear system of equations per time step and does not enforce the pointwise unit-length constraint of the magnetization. While unconditional weak convergence has been analyzed in an earlier work, we now prove optimal-order convergence rates under sufficient regularity assumptions on the exact solution and the external field. In combination with our previous work, this establishes the first higher-order-in-time and linear integrator that converges both to weak and strong solutions of LLG. Numerical experiments confirm first-order convergence in space and second-order convergence in time.

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Michele Aldé, Dirk Praetorius, Michael Feischl. 2026-05-06. BDF2-type integrator for Landau-Lifshitz-Gilbert equation in micromagnetics: a-priori error estimates. https://arxiv.org/abs/2605.05129

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