title: Phonon-pump extreme-ultraviolet-photoemission probe in graphene: anomalous heating of Dirac carriers by lattice deformation.
abstract: We modulate the atomic structure of bilayer graphene by driving its lattice at resonance with the in-plane E_{1u} lattice vibration at 6.3  μm. Using time- and angle-resolved photoemission spectroscopy (tr-ARPES) with extreme-ultraviolet (XUV) pulses, we measure the response of the Dirac electrons near the K point. We observe that lattice modulation causes anomalous carrier dynamics, with the Dirac electrons reaching lower peak temperatures and relaxing at faster rate compared to when the excitation is applied away from the phonon resonance or in monolayer samples. Frozen phonon calculations predict dramatic band structure changes when the E_{1u} vibration is driven, which we use to explain the anomalous dynamics observed in the experiment.
authors: Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany.
authors: Isabella
authors: I
authors: Gierz
authors: Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany.
authors: Matteo
authors: M
authors: Mitrano
authors: Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany.
authors: Hubertus
authors: H
authors: Bromberger
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, OX11 0QX Harwell, United Kingdom.
authors: Cephise
authors: C
authors: Cacho
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, OX11 0QX Harwell, United Kingdom.
authors: Richard
authors: R
authors: Chapman
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, OX11 0QX Harwell, United Kingdom.
authors: Emma
authors: E
authors: Springate
authors: Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany.
authors: Stefan
authors: S
authors: Link
authors: Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany.
authors: Ulrich
authors: U
authors: Starke
authors: I. Institut für Theoretische Physik, Universität Hamburg, 20355 Hamburg, Germany.
authors: Burkhard
authors: B
authors: Sachs
authors: Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany.
authors: Martin
authors: M
authors: Eckstein
authors: Institut für Theoretische Physik, Universität Bremen, 28359 Bremen, Germany.
authors: Tim O
authors: TO
authors: Wehling
authors: Institute for Molecules and Materials, Radboud University Nijmegen, 6525 HP Nijmegen, Netherlands.
authors: Mikhail I
authors: MI
authors: Katsnelson
authors: I. Institut für Theoretische Physik, Universität Hamburg, 20355 Hamburg, Germany.
authors: Alexander
authors: A
authors: Lichtenstein
authors: Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany.|Department of Physics, Clarendon Laboratory, University of Oxford, OX1 3PU Oxford, United Kingdom.
authors: Andrea
authors: A
authors: Cavalleri