Spin-polarised edge states in atomic Mn chains supported on Cu₂N/Cu (100)

Scanning tunnelling microscopy and density functional theory studies of manganese chains adsorbed on Cu₂N/Cu (100) reveal an unsuspected electronic edge state at $\sim 1$ eV above the Fermi energy. This Tamm-like state is strongly localised to the terminal Mn atoms of the chain and fully spin polarised. However, no equivalence is found for occupied states, and the electronic structure at $\sim$  −1 eV is mainly spin unpolarised due to the extended p-states of the N atoms that mediate the coupling between the Mn atoms in the chain. The spin polarisation of the edge state is affected by the antiferromagnetic ordering of the chains leading to non-trivial consequences. (letter)