Fingerprint of checkerboard antiferromagnetic order in FeSe monolayer due to magnetic-electric correlation

Abstract: Though the significance of magnetism in material properties has been well recognized, there are many difficulties and limitations in the identification techniques of magnetism. Noting the magnetic order of FeSe monolayer is important for understanding its superconductivity and remains mysterious, we take it as an example to demonstrate that electric measurements may be applied to identify the magnetic order, by utilizing the magnetic-electric correlation. The contrasts in scanning tunneling microscopy topography, superconducting gaps near defects and evolution of the electronic band structures under in-plane strain for different magnetic orders, are presented as strong evidence, or fingerprints, for the existence of checkerboard antiferromagnetic order in the FeSe monolayer observed in these experiments, and the Fe–Se–Fe exchange interaction is identified to be responsible for the correlation between Fe–Se (electric) bonding states and magnetic orders.