It is well established that the spin-orbit interaction in heavy metal/ferromagnet heterostructures leads to a significant interfacial Dzyaloshinskii-Moriya Interaction (DMI) that modifies the internal structure of magnetic domain walls (DWs) to favor N\'{e}el over Bloch type configurations. However, the impact of such a transition on the structure and stability of internal DW defects (e.g., vertical Bloch lines) has not yet been explored. We present a combination of analytical and micromagnetic calculations to describe a new type of topological excitation called a DW Skyrmion characterized by a 360∘ rotation of the internal magnetization in a Dzyaloshinskii DW. We further propose a method to identify DW Skyrmions experimentally using Fresnel mode Lorentz TEM; simulated images of DW Skyrmions using this technique are presented based on the micromagnetic results.
@article{arxiv.1809.02730,
title = {Magnetic domain wall Skyrmions},
author = {Ran Cheng and Maxwell Li and Arjun Sapkota and Anish Rai and Ashok Pokhrel and Tim Mewes and Claudia Mewes and Di Xiao and Marc De Graef and Vincent Sokalski},
journal= {arXiv preprint arXiv:1809.02730},
year = {2019}
}