Phonon modes at the reconstructed surface of a cubic lattice

Abstract

The author considers the ( square root 2* square root 2)R45 degrees -reconstruction on the (001) surface of a simple cubic lattice with interaction forces acting between nearest neighbours according to Hooke's law. Using Feynman's complex-time path integral he finds the energy of the surface, which provides the usual T2-law for specific heat. He comes to the conclusion that the energy of zero point vibrations at the surface, which can be compared to the Casimir energy, could influence the phenomenon of reconstruction at low temperatures.