Miniaturization of vortex-comprising system using ferromagnetic nanotori

摘要

The energetics associated to the ferromagnetic, vortex, and onionlike magnetization configurations are explicitly computed in the toroidal geometry. The analysis reveals that the vortex appears to be the most prominent of such states, minimizing total energy in every torus with internal radius r ≥10 nm, or even in smaller ones provided that R/e_ex≥1.5 (R is the torus external radius and e_(ex) is the exchange length). This possibility of having very small nanomagnets comprising a vortex-type state, might have importance in higher density binary logic and/or storage and in novel mechanisms for cancer therapy applications.