title: Energy-gap dynamics of superconducting NbN thin films studied by time-resolved terahertz spectroscopy.
abstract: Using time-domain terahertz spectroscopy we performed direct studies of the photoinduced suppression and recovery of the superconducting gap in a conventional BCS superconductor NbN. Both processes are found to be strongly temperature and excitation density dependent. The analysis of the data with the established phenomenological Rothwarf-Taylor model enabled us to determine the bare quasiparticle recombination rate, the Cooper pair-breaking rate and the electron-phonon coupling constant, λ=1.1±0.1, which is in excellent agreement with theoretical estimates.
authors: Department of Physics and Center for Applied Photonics, Univ. of Konstanz, D-78457, Germany.
authors: M
authors: M
authors: Beck
authors: M
authors: M
authors: Klammer
authors: S
authors: S
authors: Lang
authors: P
authors: P
authors: Leiderer
authors: V V
authors: VV
authors: Kabanov
authors: G N
authors: GN
authors: Gol'tsman
authors: J
authors: J
authors: Demsar