Ultrafast dynamics of electron-phonon coupling in correlated graphene revealed by time- and angle-resolved photoemission spectroscopy

Electron-phonon coupling plays important roles in many intriguing physics, including superconductivity, charge and spin density waves. Graphene is a model material with novel electronic properties and provide an ideal platform to study electron-phonon interactions. Despite many researches on non-equilibrium graphene electron system, the direct observation of momentum-resolved electron-phonon coupling dynamics is still missing. Here, by using time- and angle-resolved photoemission spectroscopy, we directly observe multiple electron-phonon coupling and ultrafast dynamics in correlated graphene. In addition, we observe significant suppression of decay rate induced by self-energy effects, which provide important information for controlling and understanding many-body interactions in graphene.