title: Electron cooling and debye-waller effect in photoexcited bismuth.
abstract: By means of first principles calculations, we compute the effective electron-phonon coupling constant G(0) governing the electron cooling in photoexcited bismuth. G(0) strongly increases as a function of electron temperature, which can be traced back to the semimetallic nature of bismuth. We also use a thermodynamical model to compute the time evolution of both electron and lattice temperatures following laser excitation. Thereby, we simulate the time evolution of (1 -1 0), (-2 1 1) and (2 -2 0) Bragg peak intensities measured by Sciaini et al. [Nature (London) 458, 56 (2009)] in femtosecond electron diffraction experiments. The effect of the electron temperature on the Debye-Waller factors through the softening of all optical modes across the whole Brillouin zone turns out to be crucial to reproduce the time evolution of these Bragg peak intensities.
authors: Institut de Physique de Rennes, UMR UR1-CNRS 6251, Campus de Beaulieu-Bat 11 A, 35042 Rennes Cedex, France.
authors: B
authors: B
authors: Arnaud
authors: Y
authors: Y
authors: Giret
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D004583:Electrons; D008956:Models, Chemical; D060739:Phonons; D055668:Photochemical Processes; D013696:Temperature; D013816:Thermodynamics
chemical_list: D001729:Bismuth