Phonon modes of diamond (100) surfaces fromab initiocalculations

Abstract
We present a realistic theoretical study of the surface-phonon spectra of diamond (100) surfaces. Our results reproduce the major features of the vibrational spectra of clean and hydrogenated diamond (100)-(2×1) surfaces obtained from experiments. The reconstruction of the diamond (100)-(2×1) surface yields a rich spectrum of surface modes and we identify surface features involving excitations of the surface dimer. We detail connections between atomistic surface modes and peaks observed in surface probes measuring vibrational excitations.