Uncovering unconventional hidden Rashba effect in two-dimensional InTe with inversion

The hidden Rashba (R-2) effect has been observed in centrosymmetric crystals by re-examining their spin polarization which was previously overlooked due to their inversion symmetry. Especially the R-2 effect exhibits an intriguing spin-layer locking (SLL) phenomenon in two-dimensional materials. In this research, we propose a mechanism to manipulate the spin chirality of the R-2 effect. In general, both the R-1 and R-2 effects have opposite spin chiralities in the inner and outer bands. In our newly proposed R-2 system, however, both the inner and outer bands can possess their spins with the same chirality. To materialize the new type of R-2 effect, we demonstrate a centrosymmetric InTe monolayer as a model system using first-principles density functional theory. We show that InTe possesses two pairs of the spin-degenerate R-2 Rashba bands and hosts unconventional spin chirality, with the inner and outer bands exhibiting the same chirality. We also revealed that strong spin-orbit coupling-induced band inversion between the two copies of the R-2 Rashba bands plays an important role in the formation of the unconventional spin texture. Our results also provide an exciting platform to explore the intriguing spin polarization physics from the R-2 effect.