Large deviations and transitions between equilibria for stochastic Landau-Lifshitz-Gilbert equation

Zdzislaw Brzezniak, Ben Goldys, Terence Jegaraj

Research output: Contribution to journalArticlepeer-review

Abstract

We study a stochastic Landau-Lifshitz equation on a bounded interval and with finite dimensional noise. We first show that there exists a pathwise unique solution to this equation and that this solution enjoys the maximal regularity property. Next, we prove the large deviations principle for small noise asymptotic of solutions using the weak convergence method. An essential ingredient of the proof is compactness, or weak to strong continuity, of the solution map for a deterministic Landau-Lifschitz equation, when considered as a transformation of external fields. We then apply this large deviations principle to show that small noise can cause magnetisation reversal. We also show the importance of the shape anisotropy parameter for reducing the disturbance of the solution caused by small noise. The problem is motivated by applications of ferromagnetic nanowires to the fabrication of magnetic memories.
Original languageEnglish
Pages (from-to)497–558
JournalArchive for Rational Mechanics and Analysis
Volume226
Issue number2
Early online date28 Apr 2017
DOIs
Publication statusPublished - Nov 2017

Bibliographical note

© Springer-Verlag Berlin Heidelberg 2017. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

An early version of this paper was available since 2012 at https://arxiv.org/abs/1202.0370

Keywords

  • stochastic Landau-Lifschitz equation
  • strong solutions
  • maximal regularity
  • large deviations
  • Freidlin-Ventzell estimates

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