The study investigates the impact of the electric field effect (EFE) on electron-phonon coupling in graphene, a two-dimensional carbon lattice. By modulating the charge carrier density through gate voltage, the researchers observed significant changes in the optical phonon frequencies and line widths of the G band and D* band. The EFE-induced charge density modulation leads to a linear dependence of the phonon frequency on the Fermi energy, which is attributed to the electron-phonon coupling of massless Dirac fermions. The results highlight the particle-hole symmetry around the charge-neutral Dirac point and provide insights into the fundamental interactions between electrons and lattice vibrations in graphene. The study also discusses the impact of local density variations in graphene samples and the renormalization of phonon energies due to electron-hole pair creation and annihilation. Overall, the findings demonstrate the potential of Raman spectroscopy as a tool to probe the EFE and electron-phonon coupling in graphene.The study investigates the impact of the electric field effect (EFE) on electron-phonon coupling in graphene, a two-dimensional carbon lattice. By modulating the charge carrier density through gate voltage, the researchers observed significant changes in the optical phonon frequencies and line widths of the G band and D* band. The EFE-induced charge density modulation leads to a linear dependence of the phonon frequency on the Fermi energy, which is attributed to the electron-phonon coupling of massless Dirac fermions. The results highlight the particle-hole symmetry around the charge-neutral Dirac point and provide insights into the fundamental interactions between electrons and lattice vibrations in graphene. The study also discusses the impact of local density variations in graphene samples and the renormalization of phonon energies due to electron-hole pair creation and annihilation. Overall, the findings demonstrate the potential of Raman spectroscopy as a tool to probe the EFE and electron-phonon coupling in graphene.