Density-functional theory is used to probe the spin structure of the Si(553)-Au surface. A diamagnetic $s{p}^2+p$ rehybridized structure, where the dangling bonds are either filled with two spin-paired electrons or are empty, is more favorable and in better agreement with experiment than the generally accepted spin-chain model. The shallow potential energy surface of Si(553)-Au, together with the ordered array of empty dangling bonds, suggests this surface as susceptible for spin polarization by doping, however.

• Received 6 July 2018
• Revised 13 August 2018

DOI:https://doi.org/10.1103/PhysRevB.98.121402