Spin-dependent refraction at the interface of lateral heterostructures of 2$H$-type transition-metal dichalcogenide monolayers

TL;DR

This paper investigates spin-dependent electronic refraction at interfaces of lateral heterostructures of transition-metal dichalcogenide monolayers, revealing how spin influences wave direction and enabling spin-polarized currents.

Contribution

It provides a theoretical analysis of spin-dependent refraction effects in 2H-type TMD heterostructures using first-principles and Green's function methods, highlighting the role of trigonal warping and spin-orbit coupling.

Findings

Refraction angles are close to ±30° relative to the interface.

Transmission probability increases with charge density.

Spin-dependent refraction enables spin-polarized current generation.

Abstract

We study the refraction effect of electronic wave in hole-doped lateral heterojunctions of metallic and semiconducting transition-metal dichalcogenide monolayers. This effect is theoretically investigated in 2$H$-type MoSe$_2$-NbS$_2$ and WSe$_2$-NbS$_2$ junctions by combining the first-principles calculation and the lattice Green's function method. We show that the electronic waves change the direction of motion at the interface and collimate the velocity along two different directions depending on the spin. We find that the transmission probability increases with the charge density and that the direction of refracted electron beams is close to $\pm30^\circ$ with respect to the perpendicular axis to the interface. The metallic transition-metal dichalcogenide is essential for the refraction effect because of the strong trigonal-warping effect, the large Fermi surface, and the Zeeman-type spin-orbit coupling. The refraction effect enables to generate the spin-polarized electronic current by using a simple fabrication of transition-metal dichalcogenide monolayers.