Spin-charge conversion in InSe bilayers

We find that the bilayer InSe possesses an intrinsic Rashba spin-orbit coupling and hence a spin-charge conversion effect due to the breaking of mirror symmetry. The interplay between the Rashba spin-orbit coupling and the nonparabolic Mexican hat dispersion leads to an interesting intraband Lifshitz transition and strongly amplifies the spin-charge conductivity, making it larger than that in conventional two-dimensional electron gas formed at oxide interfaces. This highlights bilayer InSe as a strong candidate for next-generation spintronic devices.