Coexistence of antiferromagnetism and superconductivity in Mn/Nb(110)

We report on the structural and magnetic properties of single and double\natomic layers of Mn on a clean and unreconstructed Nb(110) substrate.\nLow-temperature scanning tunneling spectroscopy measurements reveal a\nproximity-induced superconducting state in the Mn thin films, which are found\nto grow pseudomorphically on the Nb surface. Spin-polarized scanning tunneling\nmicroscopy measurements reveal a c(2x2) antiferromagnetic order in the Mn\nlayers, with an out-of-plane spin-orientation. First-principles density\nfunctional theory calculations confirm the experimentally observed magnetic\nstate, which is understood as the consequence of a strong intra- and\ninter-layer nearest-neighbor antiferromagnetic exchange coupling. These results\nare expected to be of importance for the design and the investigation of novel\nsuperconducting antiferromagnetic spintronic systems.\n