We report on Terahertz (THz) current oscillations in single-walled semiconducting zig-zag carbon nanotubes (CNTs) upon application of a step DC bias, as shown in Fig. 1. To investigate the electron transport on a tube with fundamental indices of
= 13 and
= 0, we developed a transient ensemble CNT Monte Carlo (MC) simulator. In the simulator, electron transport in time and space is resolved with the effects of charge distribution on the potential profile along the tube. The solution shows that electron-phonon resonances give rise to current, velocity and concentration oscillations upon application of a DC bias.