Two distinct metallic bands associated with monatomic An wires on the Si(557)-Au surface -: art. no. 081401

The Si(557)-Au surface, containing monatomic An wires parallel to the steps, has been proposed as an experimental realization of an, ideal one-dimensional metal. In fact, recent photoemission experiments on this system [Nature (London) 402, 504 (1999)] found two peaks that were interpreted in terms of the spin-charge separation in a Luttinger liquid. Our first-principles density functional calculations reveal two metallic bands associated with Au-Si bonds, instead of the single band expected from the An 6s states, providing an alternative explanation for the experimental observations.