Ultrafast electron-phonon decoupling in graphite

作者:Ishioka Kunie*; Hase Muneaki; Kitajima Masahiro; Wirtz Ludger; Rubio Angel; Petek Hrvoje
来源:Physical Review B, 2008, 77(12): 121402.
DOI:10.1103/PhysRevB.77.121402

摘要

We report the ultrafast dynamics of the 47.4 THz coherent phonons of graphite interacting with a photoinduced nonequilibrium electron-hole plasma. Unlike conventional materials, upon photoexcitation the phonon frequency of graphite upshifts, and within a few picoseconds relaxes to the stationary value. Our first-principles density functional calculations demonstrate that the phonon stiffening stems from the light-induced decoupling of the nonadiabatic electron-phonon interaction by creating a nonequilibrium electron-hole plasma. Time-resolved vibrational spectroscopy provides a window on the ultrafast nonquilibrium electron dynamics.

  • 出版日期2008-3