Electronic-magnetic phase separation in an axion insulator candidate

We propose a scanning resonant x-ray diffraction microscopy (SXDM) study to characterize mesoscale phase-separation phenomena in Eu5In2Sb6. Our interest in this structural family is due to its two perpendicular glide symmetries. On the one hand, this non-symmorphicity may give rise to topological crystalline insulating states including wallpaper fermions or the elusive axion-insulator. On the other hand, we recently discovered that these symmetries enforce complex noncollinear magnetic order that separates into compensated antiferromagnetic and weakly Ising-ferrimagnetic regimes. Neutron and muon studies and (conventional) resonant x-ray scattering have provided us with strong evidence that this mesoscale magnetism must occur on a length scale between 90nm and 15um. The real-space observation using nanofocus-SXDM will open up a range of follow-up studies, with the ultimate goal to magnetically manipulate arrangements of topologically distinct insulating domains.