Light-Enhanced Electron-Phonon Coupling in Photoexcited Graphene

This study investigates the electron-phonon coupling (EPC) in graphene, both in the ground state and under laser illumination. Using time-dependent density functional theory (TDDFT) calculations, the authors demonstrate a significant enhancement of EPC in the excited state due to the non-equilibrium distribution of photocarriers. The findings reveal that the energy transport rate and EPC strength are strongly influenced by doping concentration and that photoexcitation leads to a threefold increase in EPC strength. The mechanism of light-induced EPC enhancement is attributed to the phonon-assisted intraband transitions (PAITs) of non-equilibrium photocarriers. The study also provides a real-time tracking of ultrafast EPC dynamics, showing excellent agreement with experimental observations.

S.-Q. Hu