Minimizing cell size dependence in micromagnetics simulations with thermal noise

• Published in: Journal of physics. D, Applied physics Vol. 40; no. 4; pp. 942 - 948
• Main Authors: Martínez, E, López-Díaz, L, Torres, L, García-Cervera, C J
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 21.02.2007; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Physics; Effective field approximation; Time dependence; Fluctuations; Micromagnetism; Temperature effects; Deterministic model; Langevin equation; Ferromagnetic materials; Thermal noise; Nanostructures; Thermodynamic equilibrium
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/40/4/003

Langevin dynamics treats finite temperature effects in a micromagnetics framework by adding a thermal fluctuation field to the effective field. Several works have addressed the dependence of numerical results on the cell size used to split the ferromagnetic samples on the nanoscale regime. In this paper, some former problems dealing with the dependence on the spatial discretization at finite temperature have been revised. We have focused our attention on the stability of the numerical schemes used to integrate the Langevin equation. In particular, a detailed analysis of results was carried out as a function of the time step. It was confirmed that the mentioned dependence can be minimized if an unconditional stable integration method is used to numerically solve the Langevin equation.