Giant spin Hall Effect in two-dimensional monochalcogenides

TL;DR

This paper reports the discovery of giant, tunable intrinsic spin Hall conductivities in two-dimensional group-IV monochalcogenides, revealing their potential for highly adaptable spintronics applications through strain and doping manipulation.

Contribution

First-principles calculations demonstrate giant, tunable spin Hall effects in 2D monochalcogenides, highlighting their suitability for advanced spintronics device design.

Findings

Giant intrinsic spin Hall conductivities in MX monolayers.

Strain and doping can tune the spin Hall resonances.

Strain can induce semiconductor-metal transitions enabling spin Hall effects without doping.

Abstract

One of the most exciting properties of two dimensional materials is their sensitivity to external tuning of the electronic properties, for example via electric field or strain. Recently discovered analogues of phosphorene, group-IV monochalcogenides (MX with M = Ge, Sn and X = S, Se, Te), display several interesting phenomena intimately related to the in-plane strain, such as giant piezoelectricity and multiferroicity, which combine ferroelastic and ferroelectric properties. Here, using calculations from first principles, we reveal for the first time giant intrinsic spin Hall conductivities (SHC) in these materials. In particular, we show that the SHC resonances can be easily tuned by combination of strain and doping and, in some cases, strain can be used to induce semiconductor to metal transitions that make a giant spin Hall effect possible even in absence of doping. Our results indicate a new route for the design of highly tunable spintronics devices based on two-dimensional materials.