Atomistic spin dynamics in symmetric interfaces with complex magnetic nanostructures: investigation of interdiffusion effects

Abstract

This project is imbricated in a FAPESP funded Ph.D. project which proposes the study of magnetic materials with potential applications in spintronics. The investigations foreseen in this internship in Sweden shall focus on the formation of skyrmions in symmetric multilayers. The present project has been developed through a close collaboration with an experimental group in Brazilian Synchrotron Light Laboratory (LNLS) and a very intriguing question has been raised which requires further theoretical tools to be investigated. Although, the Dzyaloshinskii-Moriya interaction (DMI) is expected to be null in the presence of inversion symmetry, a non-null DMI along with a large perpendicular magnetic anisotropy (PMA) has been reported to be responsible for the stabilization of room temperature spontaneous skyrmions in Pd/Co/Pd multilayers. In order to investigate the origin of an unusual non-null DMI in this system, the simulation of interdiffusion effects at the interface Pd/Co is suggested in this project. It is foreseen that these deep investigations and comparative analysis allow us to establish which are the contributions to the formation of room temperature spontaneous skyrmions in symmetric samples. The state-of-art theoretical arsenal for in silico simulations of these systems will be applied: the DFT based RS-LMTO-ASA method, for the calculation of impurities at the Pd/Co layers, in order to simulate a rough interface, and the UppASD code, for Spin Dynamics simulations, to predict the emergence of skyrmions at room temperature. The complexity and novelty of exploring the origin of a non-null DMI in symmetric layers and simulating interdiffusion effects using Spin Dynamics calculations are the great challenges addressed in the present project. Further applications to investigate other promising systems are also foreseen. (AU)