Contributions to Books:
G. Di Fratta, A. Jüngel, D. Praetorius, V. Slastikov:
"Spin-diffusion model for micromagnetics in the limit of long times";
in: "ASC Report 26/2020",
issued by: Institute for Analysis and Scientific Computing;
Vienna University of Technology,
In this paper, we consider spin-diffusion Landau-Lifshitz-Gilbert equations (SDLLG), which consist of the time-dependent Landau-Lifshitz-Gilbert (LLG) equation coupled with a time-dependent diffusion equation for the electron spin accumulation. The model takes into account the diffusion process of the spin accumulation in the magnetization dynamics of ferromagnetic multilayers. We prove that in the limit of long times, the system reduces to simpler equations
in which the LLG equation is coupled to a nonlinear and nonlocal steady-state equation, referred to as SLLG. As a by-product, the existence of global weak solutions to the SLLG equation is obtained. Moreover, we prove weak-strong uniqueness of solutions of SLLG, i.e., all weak solutions coincide with the (unique) strong solution as long as the latter exists in time. The results provide a solid mathematical ground to the qualitative behavior originally predicted by Zhang, Levy, and Fert in [Physical Review Letters 88 (2002)] in ferromagnetic multilayers.
Micromagnetics, Landau-Lifshitz-Gilbert equation, spin diffusion, asymptotic analysis, existence of solutions, weak-strong uniqueness.
Electronic version of the publication:
Created from the Publication Database of the Vienna University of Technology.