Electron Energy Relaxation in (Cd_(1-x)Zn_x)_3As_2 Dirac Semimetals Studied by Terahertz Laser Pulses

摘要

We performed a study of a range of (Cd_(1-x)Zn_x)_3As_2 mixed crystals undergoing a transition from the Dirac semimetal phase to trivial semiconductor at variation of the composition x. We show that for the Dirac semimetal phase, the photoelectromagnetic effect amplitude is defined by the number of incident radiation quanta, whereas for the trivial semiconductor phase, it depends on the power in a laser pulse irrespective of its wavelength. We assume that such behavior is attributed to formation of surface electron states with a spin texture in Dirac semimetals.