Electronic structure of a buried two-dimensional antiferromagnetic layer: Experimental and theoretical investigation of Ag/Cr/Ag(001)

Abstract

We have investigated the electronic structure of monolayer Cr deposited on Ag(001), using angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations. It is favorable for the Cr layer to be buried one layer deep, resulting in a 1 Ag/1 Cr/Ag(001) sandwich structure with the moments on the Cr atoms aligned antiferromagnetically in a c(2 × 2) arrangement. Both experiment and theory agree well on the measured/calculated band dispersions and their intensities. Two relatively flat bands arise from antiferromagnetic Cr 3d states; in addition, quantum well states with strong curvatures are prominent near both the X and M points of the surface Brillouin zone. Our results suggest that the buried Cr monolayer in Ag(001) could serve as a prototypical system to study two-dimensional antiferromagnetism in the presence of weak electronic correlation effects