Equilibrium magnetization configurations in helical magnets

Abstract

We have taken an in-depth study of curvature effects on the magnetism of low dimensional nanostructures. We present a general theoretical framework based on a continuous approach to the micromagnetic relevant energy terms (exchange and anisotropy). The model shows that curvature induces effective anisotropy and Dzyaloshinskii-Moriya interactions that are not present in conventional cases. We have particularized the study to helical ferromagnetic helices, and found that they exhibit stable magnetization transitions between quasi-tangential to onion-like configurations. By performing atomistic Monte Carlo simulations, we have validated the theoretical framework and obtained a phase diagram of both phases. We have also performed MC simulations considering only dipolar interactions and found that abrupt magnetic ground state configuration transitions can be induced