title: Slow Noncollinear Coulomb Scattering in the Vicinity of the Dirac Point in Graphene.
abstract: The Coulomb scattering dynamics in graphene in energetic proximity to the Dirac point is investigated by polarization resolved pump-probe spectroscopy and microscopic theory. Collinear Coulomb scattering rapidly thermalizes the carrier distribution in k directions pointing radially away from the Dirac point. Our study reveals, however, that, in almost intrinsic graphene, full thermalization in all directions relying on noncollinear scattering is much slower. For low photon energies, carrier-optical-phonon processes are strongly suppressed and Coulomb mediated noncollinear scattering is remarkably slow, namely on a ps time scale. This effect is very promising for infrared and THz devices based on hot carrier effects.
authors: Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany.|Technische Universität Dresden, 01062 Dresden, Germany.
authors: J C
authors: JC
authors: König-Otto
authors: University of Maryland, College Park, Maryland 20742, USA.
authors: M
authors: M
authors: Mittendorff
authors: Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
authors: T
authors: T
authors: Winzer
authors: Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
authors: F
authors: F
authors: Kadi
authors: Chalmers University of Technology, SE-41296 Göteborg, Sweden.
authors: E
authors: E
authors: Malic
authors: Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin, Germany.
authors: A
authors: A
authors: Knorr
authors: Georgia Institute of Technology, Atlanta, Georgia 30332, USA.|Institut Néel, CNRS-Université Alpes, 38042 Grenoble, France.
authors: C
authors: C
authors: Berger
authors: Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
authors: W A
authors: WA
authors: de Heer
authors: Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany.
authors: A
authors: A
authors: Pashkin
authors: Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany.
authors: H
authors: H
authors: Schneider
authors: Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany.|Technische Universität Dresden, 01062 Dresden, Germany.
authors: M
authors: M
authors: Helm
authors: Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany.
authors: S
authors: S
authors: Winnerl