3:15 PM - 3:30 PM
[26p-E101-9] Electron-optical phonon coupling in graphene investigated by time-resolved terahertz spectrsocpy
Keywords:graphene, terahertz spectroscopy, electron-phonon coupling
In graphene, there two dominant optical phonon modes which participate the energy dissipation of hot carriers created after photoexcitation. One is E2 mode near G point for intra-valley carrier scattering and the other is A1 mode near K-point for inter-valley carrier scattering. The electron-phonon coupling (EPC) for A1 mode has been debated because it was predicted to be enhanced by the electron-electron renormalization effect. In this study, we successfully evaluated the EPC of A1 mode as 45000 (eV/nm)2 by using the time-resolved terahertz spectroscopy. The obtained value is approximately 5 time higher than that obtained by the density functional perturbation theory and indicates the strong coulomb renormalization effect on the EPC.