Magnetic circular dichroism imaging of atomic-scale antiferromagnetic order at a buried interface

Magnetic circular dichroism utilizing electrons or X-rays serves as a powerful tool for the investigation of magnetism in ferromagnets, but antiferromagnets pose a severe challenge to the technique due to their vanishing net magnetization. Although transmission electron microscopy has demonstrated the atomic-scale characterization of antiferromagnetism using elastically scattered electrons, separating the weak magnetic signal from the dominant electrostatic background remains challenging, and applicability is largely limited to perfect crystals. Here we develop atomic-column-resolved electron magnetic circular dichroism to resolve antiferromagnetic order using a scanning transmission electron microscope. By exploiting chirality around individual magnetic atomic columns, we localize the magnetic circular dichroism signals around the transmitted electron beam with enhanced strength and signal-to-noise ratio, enabling atomic-column magnetic measurements. Applying this technique to antiferromagnets, we not only distinguish the characteristic G-type and C-type antiferromagnetic orderings in DyFeO₃ and α-Fe₂O₃ but also identify a one-unit-cell-thick magnetic dead layer at the buried DyScO₃-SmFeO₃ interface. Our work establishes a readily accessible method for atomic-scale magnetic order mapping, with potential applications in fields such as interfacial magnetism, topological magnetism, antiferromagnetism and altermagnetism.