We present a first microscopic study of the state of a semiconductor surface, clean Ge(111), close to the bulk melting temperature. Both electronic states and ionic motion are fully treated via first-principles molecular dynamics. Results indicate a clear dynamical disordering, confined, however, to the first atomic bilayer. This region acquires a liquidlike diffusion, and is metallic. Lack of melting of the second and deeper bilayers, found to be in good quantitative agreement with recent x-ray data, indicates an incomplete wetting of the semiconducting solid by its own metallic melt. Previously conflicting data on Ge(111) are also reconciled within this picture.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)