title: Optical characterization of electron-phonon interactions at the saddle point in graphene.
abstract: The role of many-body interactions is experimentally and theoretically investigated near the saddle point absorption peak of graphene. The time and energy-resolved differential optical transmission measurements reveal the dominant role played by electron-acoustic phonon coupling in band structure renormalization. Using a Born approximation for electron-phonon coupling and experimental estimates of the dynamic lattice temperature, we compute the differential transmission line shape. Comparing the numerical and experimental line shapes, we deduce the effective acoustic deformation potential to be Deff(ac)≃5  eV. This value is in accord with recent theoretical predictions but differs from those extracted using electrical transport measurements.
authors.affiliation: College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA and U.S. Army Aviation and Missile Research, Development, and Engineering Center, Redstone Arsenal, Alabama 35898, USA.
authors.forename: Adam T
authors.initials: AT
authors.lastname: Roberts
authors.affiliation: College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA and Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Rolf
authors.initials: R
authors.lastname: Binder
authors.affiliation: College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Nai H
authors.initials: NH
authors.lastname: Kwong
authors.affiliation: Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Golla
authors.affiliation: Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cormode
authors.affiliation: Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: LeRoy
authors.affiliation: U.S. Army Aviation and Missile Research, Development, and Engineering Center, Redstone Arsenal, Alabama 35898, USA.
authors.forename: Henry O
authors.initials: HO
authors.lastname: Everitt
authors.affiliation: College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA and Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Arvinder
authors.initials: A
authors.lastname: Sandhu