Intrinsic spin-valley locking for conducting electrons in metal-semiconductor-metal lateral hetero-structures of $1H$-transition-metal dichalcogenides

TL;DR

This paper theoretically demonstrates that metal-semiconductor-metal lateral hetero-structures of $1H$-transition-metal dichalcogenides inherently host spin-valley locked conducting channels, enabling valley-dependent spin control and high transmission in electronic devices.

Contribution

It reveals the intrinsic spin-valley locking in lateral hetero-structures of $1H$-transition-metal dichalcogenides and analyzes their electronic transport properties, including high transmission and step-like I-V characteristics.

Findings

Hetero-structures produce valley-specific conducting channels.

Spin of electrons is restricted by valley-dependent charge transfer.

WSe$_2$ hetero-junction shows high transmission for valley-spin locked electrons.

Abstract

Lateral-hetero structures of atomic layered materials alter the electronic properties of pristine crystals and provide a possibility to produce useful monolayer materials. We reveal that metal-semiconductor-metal lateral-hetero junctions of $1H$-transition-metal dichalcogenides intrinsically possess conducting channels of electrons with spin-valley locking, e.g., gate electrode. We theoretically investigate the electronic structure and transport properties of the lateral-hetero junctions and show that the hetero-structure produces conducting channels through the $K$ and $K'$ valleys in the semiconducting transition-metal dichalcogenide and restricts the spin of the conducting electrons in each valley due to the valley dependent charge transfer effect. Moreover, the theoretical investigation shows that the hetero-junction of WSe$_2$ realizes a high transmission probability for valley-spin locked electrons even in a long semiconducting region. The hetero-junction also provides a useful electronic transport property, a step-like I-V characteristic.