Descripció
Authors: J. Castell-Queralt, L. González-Gómez, N. del-Valle, C. Navau, Physics, Universitat Autonoma de Barcelona Facultat de Ciencies, Barcelona, Catalunya, SPAIN|
Abstract Body: The finding of skyrmions at room temperature has boosted the potentiality of skyrmionic devices. From the theoretical point of view, the temperature in micromagnetic systems has been taken into account either using stochastic spin dynamics, the stochastic Landau-Lifshitz equation, or the Landau-Lifshitz-Block equation. Also, the rigid model has been used to describe the skyrmion dynamics taking into account thermal effects, using the stochastic Thiele equation [1]. Here we present a deterministic method to study the skyrmion dynamics [2], an approach in which the temporal motion of skyrmions can be studied without relying on repetition of stochastic simulations, but on solving once the associated deterministic Fokker-Planck equation. This is a substantial advance, since by finding and solving a single partial differential equation, one could obtain all the relevant probabilistic information of the system. Indeed, within the rigid approximation, the probability density for the presence of skyrmions under any external potential can be found at any time and position, and as a function of the temperature. This allows one to evaluate the probability of presence/survival trapping/escaping ... of skyrmions in many practical situations, which is a key information to ensure the viability of applications. In particular, the probability of trapping/escaping of a skyrmion that encounters a pinning site, and the probability of survival of a skyrmion along a track are presented as a function of temperature.References: [1] D. Pinna, F. Abreu Araujo, J. Grollier, Phys. Rev. Applied., Vol. 9, (2018) [2] J. Castell-Queralt, L. González-Gómez, C. Navau. Phys. Rev. B 101, 140404 (R) (2020)
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Abstract Body: The finding of skyrmions at room temperature has boosted the potentiality of skyrmionic devices. From the theoretical point of view, the temperature in micromagnetic systems has been taken into account either using stochastic spin dynamics, the stochastic Landau-Lifshitz equation, or the Landau-Lifshitz-Block equation. Also, the rigid model has been used to describe the skyrmion dynamics taking into account thermal effects, using the stochastic Thiele equation [1]. Here we present a deterministic method to study the skyrmion dynamics [2], an approach in which the temporal motion of skyrmions can be studied without relying on repetition of stochastic simulations, but on solving once the associated deterministic Fokker-Planck equation. This is a substantial advance, since by finding and solving a single partial differential equation, one could obtain all the relevant probabilistic information of the system. Indeed, within the rigid approximation, the probability density for the presence of skyrmions under any external potential can be found at any time and position, and as a function of the temperature. This allows one to evaluate the probability of presence/survival trapping/escaping ... of skyrmions in many practical situations, which is a key information to ensure the viability of applications. In particular, the probability of trapping/escaping of a skyrmion that encounters a pinning site, and the probability of survival of a skyrmion along a track are presented as a function of temperature.References: [1] D. Pinna, F. Abreu Araujo, J. Grollier, Phys. Rev. Applied., Vol. 9, (2018) [2] J. Castell-Queralt, L. González-Gómez, C. Navau. Phys. Rev. B 101, 140404 (R) (2020)
https://s3.eu-west-1.amazonaws.com/underline.prod/uploads/markdown_image/1/image/41c33a46e8dd725537f062d18647acdc.jpg
| Data disponible | 15 d’oct. 2020 |
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