Hot carrier dynamics in monolayer graphene studied by optical pump/ultra-broadband THz probe spectroscopy

Hot carrier dynamics in single-layered doped graphene after the photo-excitation has been studied by ultra-broadband optical-pump/THz-probe spectroscopy (OPTP). We successfully determined the frequency-dependent carrier scattering rate Γ(ω) and Drude weight D(o) of photo-excited graphene from 1 to 8 THz. The Γ(ω) shows a strong frequency dependence and the reduction of the averaged D(o) cannot be explained by the simple carrier temperature model previously reported [1], indicating the many body effects should be taken into account for the hot carrier dynamics in single-layered graphene.