title: Ultrafast Fano resonance between optical phonons and electron-hole pairs at the onset of quasiparticle generation in a semiconductor.
abstract: Based on the many-body time-dependent approach applied to the ultrafast time region, we investigate the dynamics of creation of an optical phonon incorporating with the electron-hole continuum in a semiconductor. In the transient Fano resonance, due to an interference between those sharp (optical phonon) and continuum (electron-hole pair) quasiparticles, we find the robust destructive interference at birth of them, i.e., tau approximately 0 if the created phonon is coherent under the irradiation of ultrashort optical pulses. The origin is found to be the potential scattering of the electron-hole pair by the q=0 coherent phonon. This finding agrees well with the recent experiment.
authors.affiliation: International Center for Young Scientists, National Institute for Materials Science, Tsukuba 305-0044, Japan.
authors.forename: J D
authors.initials: JD
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Inoue
authors.forename: Muneaki
authors.initials: M
authors.lastname: Hase