Electric field modulated valley- and spin-dependent electron retroreflection and Klein tunneling in a tilted n-p-n junction of monolayer 1T'-MoS2

We study the electronic transport properties in a tilted n-p-n junction of monolayer 1T'-MoS2 under a vertical electric field. The analytical derivations and numerical results show that, since the spin degeneracy of the anisotropic bands of monolayer 1T'-MoS2 is lifted by the electric field E-z, electrically tunable valley-and spin-dependent electron retroreflection occurs in the tilted n-p-n junction. It is also found that when the electric field E-z is adjusted to a critical value E-c, valley-and spin-dependent Klein tunneling happens in the n-p-n junction, and the incident angle of Klein tunneling depends on the tilt angle of the junction. Especially, for a certain specific tilt angle, in the case of normal incidence, only a spin-up electron from the K valley can undergo Klein tunneling. Our work offers an efficient mechanism to modulate valley-and spin-dependent electron retroreflection and Klein tunneling in anisotropic tilted Dirac systems.

Automated summary

We investigate the electronic transport properties of a tilted n-p-n junction in monolayer 1T'-MoS2 under a vertical electric field. Our analytical and numerical results demonstrate that the electric field E-z lifts the spin degeneracy of the anisotropic bands in monolayer 1T'-MoS2, leading to electrically tunable valley-and spin-dependent electron retroreflection in the tilted n-p-n junction. We also observe valley-and spin-dependent Klein tunneling in the n-p-n junction when the electric field E-z reaches a critical value E-c, and the incident angle of Klein tunneling depends on the tilt angle of the junction. Furthermore, we find that only spin-up electrons from the K valley can undergo Klein tunneling for a certain specific tilt angle under normal incidence. Our study provides an efficient mechanism to manipulate valley-and spin-dependent electron retroreflection and Klein tunneling in anisotropic tilted Dirac systems.