Tunable Intrinsic Spin Hall Conductivity in Two-Dimensional van der Waals Ferroelectric WTe2

We conducted a systematic study of the spin Hall conductivity (SHC) of bilayer WTe2 and investigated the effects of interlayer sliding and interlayer distance on the SHC. We discovered that while the SHC is robust against changes in interlayer sliding, it can be tuned by adjusting the distance between the layers. We found that the interlayer distance-dependent SHC arises from interlayer coupling, which determines the hybridization strength of W-d and Te-p orbitals and subsequently affects the SHC. Therefore, changing the distance between layers in bilayer WTe2 can effectively tune the SHC. These findings not only enhance our fundamental understanding of the SHC in bilayer WTe2 but also provide guidelines for the development of next-generation spintronic devices.