Magnetic surface reconstruction in the van der Waals antiferromagnet Fe 1 + x Te

Fe${}_{1+x}$Te is a two-dimensional van der Waals antiferromagnet that becomes superconducting on anion substitution on the Te site. Here, the authors present results from spherical neutron polarimetry and scanning tunneling microscopy probing bulk and surface magnetic structures, respectively. While both surface and bulk structures are collinear, the surface magnetism displays a large canting, not found with spherical neutron polarimetry. The authors demonstrate that Fe${}_{1+x}$Te exhibits a surface magnetic reconstruction when the symmetry constraints of the bulk are removed.