Strain modulation of intrinsic spin hall conductivity in monolayer 1T TaS2 and Graphene/TaS2 interface: The role of orbital texture

The conductive monolayer 1T TaS2 is a promising candidate to promote spintronic devices to the next level. Through first-principle calculations, we demonstrate that the intrinsic spin Hall conductivity (ISHC) in conductive monolayer 1T TaS2 and its interfaces with graphene can be engineered by strain through manipulating the orbital texture of the material. First, we quantitatively study orbital hybridization in monolayer TaS2 under compressive and tensile strains. Next, by calculating the spin Berry curvature (SBC) of the bands over the whole BZ, we investigate the spin Hall conductivity of the pristine and strained monolayer TaS2. With a detailed analysis of the band structure and characterizing the change in the concavity of the bands in the vicinity of the Fermi level, we identify the responsible features for the tunable ISHC to be hybridization strength in conjugation with spin-orbit coupling (SOC). Furthermore, our SBC projected band structure calculations point toward an interesting correlation between the magnitude of the ISHC and the pd hybridization strength. Inspired by the correlation between orbital hybridization and ISHC values, we next look at the heterostructure of graphene and monolayer TaS2. Our calculations show that upon orbital mixing between the two materials, a large ISHC of 235 h/e Omega(-1)cm(-1) can be realized which is comparable to many pioneering materials with spintronic applications. These findings suggest possible routes to design novel materials for spintronic application via engineering the orbital texture of the bands.