Renormalized acoustic branch in the vibrational spectrum of theπ-bonded–chain model of Si(111)21
- 10 August 1987
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 59 (6) , 657-660
- https://doi.org/10.1103/physrevlett.59.657
Abstract
We calculate the low-frequency phonon spectrum of the π-bonded–chain model of the Si(111)2×1 surface, and find an explanation for the surprising observation, in He-atom scattering experiments, of a low-energy dispersionless surface phonon. This feature results from strong electron polarization effects, which arise from the quasi one-dimensional nature of the π-bonded–chain model. The assignment of this mode as an Einstein oscillator is incorrect. Our calculations are based on Chadi’s tight-binding theory for structural energies, with the addition of a Hubbard interaction.Keywords
This publication has 15 references indexed in Scilit:
- Optical properties and atomic structure of cleaved silicon and germanium (111) surfacesSurface Science Reports, 1986
- Observation of a 10-meV Einstein Oscillator Mode on the Si(111) (2×1) SurfacePhysical Review Letters, 1986
- Polarization dependence of Si(111)-2×1 surface-phonon and surface-state excitationsPhysical Review B, 1986
- Angle dependence of inelastic electron cross sections for parallel-oriented dipole scatterersSurface Science, 1986
- Dipole Activity of Surface Phonons on Si(111)2×1Physical Review Letters, 1985
- Conduction-Band and Surface-State Critical Points in Si: An Inverse-Photoemission StudyPhysical Review Letters, 1985
- New-Bonded Chain Model for Si(111)-(2×1) SurfacePhysical Review Letters, 1981
- Surface states on Si(111)-(2×1)Physical Review B, 1981
- Energy-Minimization Approach to the Atomic Geometry of Semiconductor SurfacesPhysical Review Letters, 1978
- Surface Vibrations of Silicon Detected by Low-Energy Electron SpectroscopyPhysical Review Letters, 1971