Study of Skyrmions Behavior in Magnetic Materials with Defects

Abstract

In this work we will study the dynamical behavior of skyrmions on the presence of different defects configurations.Proposed initially by the english physicist Tony Skyrme, skyrmions are quasi-particles corresponding to a spin distribution pointing in all directions wrapping a sphere. It formation is primordially by two concurrent interactions: the ferromagnetic exchange and the Dzyaloshinskii-Moriya interaction. More recently, skyrmion have been found in magnetic materials. Skyrmions are set to motion by applying a spin polarized current, and the current density needed for starting its motion is 4 to 5 orders of magnitude smaller when compared to the current density necessary to move Bloch walls. Furthermore, skyrmions shows smaller sizes, on the order of some nanometers in MnSi at low temperatures. This makes skyrmions excellent for applications on spintronics, since there is a low energy cost and potential for higher density associate with it.A good understanding of skyrmion dynamics on the presence of different defects configurations, as well as deformations, annihilation and creation of skyrmions, are essential for future technological applications. On the present project, using the atomistic model, we will simulate the skyrmion behavior interacting with defects applying a spin polarized current.