Ultrafast carrier generation in Bi1-xSbx thin films induced by intense monocycle terahertz pulses

Using terahertz-pump and terahertz-probe spectroscopy, we investigated terahertz-induced carrier generation processes in Bi 1- x Sb x thin films. The field dependence of the terahertz-induced transmittance change indicates distinct nonlinearity related to the Zener tunneling in narrow band-gap materials.