In this paper, we present direct time-domain investigations of the relaxation of electric currents in graphene due to hot copyright scattering.We use coherent control with ultrashort optical pulses to photoinject a current and detect the terahertz Semi Flush Mount (THz) radiation emitted by the resulting current surge.We pre-inject a background of hot carriers using a separate pump pulse, with a variable delay between the pump and current-injection pulses.
We find the effect of the hot copyright background is to reduce the current and hence the emitted THz radiation.The current damping is determined simply by the density (or temperature) of the thermal carriers.The experimental behavior is accurately reproduced in a microscopic theory, which correctly incorporates the nonconservation of velocity in scattering between Dirac fermions.
The results indicate that hot carriers are effective in damping the current, and Acrylic Name Night Light are expected to be important for understanding the operation of high-speed graphene electronic devices.