Circular Dichroism in Resonant Photoelectron Diffraction from an Antiferromagnetic Monolayer on a Honeycomb Lattice

Circular dichroism (CD) in resonant photoelectron diffraction (RPED) has recently been identified as a direct probe of the surface magnetic structure of altermagnets. Here the CD-RPED of a two-dimensional antiferromagnet on a honeycomb lattice is calculated for a manganese monolayer, by combining atomic multiplet and multiple scattering theory. While the XMCD is strictly zero for this system, the RPED pattern at the Mn-L3 edge resonance displays a large CD of dominantly magnetic origin. Even with non-polarized light, there is a magnetic contrast between antiferromagnetic domains of opposite Néel vector. The findings show that CD-RPED gives detailed magnetic information not only for altermagnets but also for other compensated collinear magnetic structures with spin-density wave vector q＝0.