Electron dynamics in a gold thin film accelerated via an intense terahertz field

We observed the nonlinear electron dynamics in polycrystalline gold (Au) thin films via intense terahertz spectroscopy. Under the intense terahertz wave illumination, the transmittance of Au thin film decreases, indicating that the damping constant of electrons becomes smaller due to the suppression of the grain-boundary effect on electrons induced by the intense terahertz field.