Spin Hall Effect and Weak Antilocalization in Graphene/Transition Metal Dichalcogenide Heterostructures

Abstract

We report on a theoretical study of the spin Hall Effect (SHE) and weak antilocalization (WAL) in graphene/transition metal dichalcogenide (TMDC) heterostructures, computed through efficient real-space quantum transport methods, and using realistic tight-binding models parametrized from ab initio calculations. The graphene/WS 2 system is found to maximize spin proximity effects compared to graphene on MoS 2 , WSe 2 , or MoSe 2 , with a crucial role played by disorder, given the disappearance of SHE signals in the presence of strong intervalley scattering. Notably, we found that stronger WAL effects are concomitant with weaker charge-to-spin conversion efficiency. For further experimental studies of graphene/TMDC heterostructures, our findings provide guidelines for reaching the upper limit of spin current formation and for fully harvesting the potential of two-dimensional materials for spintronic applications.

Spin and Charge Transport of Multiorbital Quantum Spin Hall Insulators

“…Here we shall make use of Chebyshev polynomial expansions 31,32 for this purpose. This real-space method has been employed with great success to analyse quantum transport properties of two dimensional systems [33][34][35][36][37] , by virtue of its high accuracy, stability and scalability. We Results of our tight-binding calculations for the density of states ρ and σ s xy as functions of energy are shown in panel (c) of Fig.…”

Quantum Spin Hall Materials

“…QSH effect is also predicted in graphene interacting with single crystal WS 2 or WSe 2 . Experimentally, such heterostructures show promising features with a substantial enhancement in the spin–orbit coupling strength in graphene …”

“…[74] Experimentally, such heterostructures show promising features with a substantial enhancement in the spin-orbit coupling strength in graphene. [141][142][143][144][145]…”

Van Der Waals Heterostructures with Spin‐Orbit Coupling

“…It has also been suggested that by tuning the twist angle between graphene and the TMD the nature, from Zeeman‐like to Rashba‐like, and strength of the induced SOC can be tuned . Similarly to the case of graphene‐TI systems, spin and charge transport are also coupled in graphene‐TMD heterostructures as demonstrated experimentally in graphene‐MoS 2 , graphene‐WS 2 , graphene‐MoTe 2 , and graphene‐TaS 2 devices.…”

“…[122][123][124][125][126] It has also been suggested that by tuning the twist angle between graphene and the TMD the nature, from Zeeman-like to Rashba-like, and strength of the induced SOC can be tuned. [127,128] Similarly to the case of graphene-TI systems, spin and charge transport are also coupled in graphene-TMD heterostructures [129,130] as demonstrated experimentally in graphene-MoS 2 , [131,132] graphene-WS 2 , [133,134] graphene-MoTe 2 , [135] and graphene-TaS 2 [136] devices. For the case of TMD-BLG vdW systems the resulting structure of the hybridized bands is richer and tunable via an external electric field.…”