Minimal time of magnetization switching in small ferromagnetic ellipsoidal samples - Archive ouverte HAL Accéder directement au contenu
Pré-Publication, Document De Travail Année : 2023

Minimal time of magnetization switching in small ferromagnetic ellipsoidal samples

Résumé

In this paper, we consider a ferromagnetic material of ellipsoidal shape. The associated magnetic moment then has two asymptotically stable opposite equilibria, of the form $\pm\overline{m}$. In order to use these materials for memory storage purposes, it is necessary to know how to control the magnetic moment. We use as a control variable a spatially uniform external magnetic field and consider the question of flipping the magnetic moment, i.e., changing it from the $+\overline{m}$ configuration to the $-\overline{m}$ one, in minimal time. Of course, it is necessary to impose restrictions on the external magnetic field used. We therefore include a constraint on the $L^\infty$ norm of the controls, assumed to be less than a threshold value $U$. We show that, generically with respect to the dimensions of the ellipsoid, there is a minimal value of $U$ for this problem to have a solution. We then characterize it precisely. Finally, we investigate some particular configurations associated to geometries enjoying symmetries properties and show that in this case the magnetic moment can be controlled in minimal time without imposing a threshold condition on $U$.
Fichier principal
Vignette du fichier
min_Time_Switch_CCFP.pdf (1.81 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03931579 , version 1 (09-01-2023)

Identifiants

Citer

Raphaël Côte, Clémentine Courtès, Guillaume Ferriere, Yannick Privat. Minimal time of magnetization switching in small ferromagnetic ellipsoidal samples. 2023. ⟨hal-03931579⟩
114 Consultations
40 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More