Ferromagnetism and skyrmions in the intrinsic magnetic topological insulator MnSb(2)Te(4)

The correlation between magnetic order and nontrivial topological order is at the heart of the technological developments towards quantum computation, quantum metrology and dissipationless transport. In this context, novel topological states in quantum anomalous Hall effect (QAHE) systems and in axion insulators are exciting, yet experimentally elusive quantum systems. A little studied but extremely interesting phenomenon is the potential occurrence of skyrmions, a real space realization of topological states, in systems which are simultaneously prone to exhibiting the QAHE such as the Mn(Bi,Sb)(n+1)Te(3n+1) family. Here we propose to combine surface-sensitive x-ray absorption spectroscopy and x-ray magnetic circular dichroism at the Mn L2,3 edge in TEY mode with bulk sensitive FY as well as SQUID magnetometry studies to reveal the local magnetic and electronic properties of the Mn ions in the bulk and near the surface of the three well characterized samples showing to exhibit skyrmion-like magnetic domains.