Terahertz radiation of jerk photocurrent

Abstract

We compute the jerk current tensor of GaAs, Si, and ferroelectric single-layer GeS, GeSe, SnS, and SnSe. We find peak values of the order of $10^{14}$ mA/V$^3$s$^2$ in GaAs and Si within the visible energy spectrum and an order of magnitude larger in single-layer GeS, GeSe, SnSe and SnS. We show that the detailed knowledge of this tensor and its large value in single-layer GeS, GeSe, SnSe and SnS make it possible to predict the magnitude and angle of rotation of polarization of intense terahertz pulses generated in photoconductive switches and point to alternative functionalities of these devices.