title: Electromagnetic excitation of phonons at C(001) surfaces.
abstract: The photon-phonon coupling at C(001)-(2 × 1) surfaces and its manifestation in far-infrared reflectance anisotropy spectra (FIR-RAS) are theoretically investigated. We solve the coupled system of equations for the electromagnetic field and lattice vibrations, described within the adiabatic bond charge model (ABCM), with the method of expansion into bulk phonon and photon modes. The calculated FIR-RAS exhibit resonances associated with zone-center surface phonons in good agreement with available HREELS experiments and predictions of vibrational modes for diamond (001)-(2 × 1) surfaces from ABCM and ab initio calculations. Interestingly, the reflectance anisotropy spectra for a C(001)-(2 × 1) surface turn out to be qualitatively different from the spectra for a Si(001)-(2 × 1) surface, reported previously.
authors.affiliation: Escuela de Ciencias, Universidad Autónoma 'Benito Juárez' de Oaxaca, Avenida Universidad S/N, Ex-Hacienda de Cinco Señores, Ciudad Universitaria, Oaxaca de Juárez, Oaxaca, 68120, Mexico.
authors.forename: F L
authors.initials: FL
authors.lastname: Pérez-Sánchez
authors.forename: F
authors.initials: F
authors.lastname: Pérez-Rodríguez