Giant spin splitting induced by a symmetry-braking van der Waals interaction

It is shown, based on the density functional theory (DFT) calculations, that weak van der Waals interaction between monolayers of Pb and MoTe₂ introduce a symmetry breaking that gives rise to spin polarized interface states. This is a departure from a conventional picture of band spin splitting in the adsorption systems as it is usually associated with the strong surface interactions e.g. covalent bonds, which results in electronic charge asymmetry in the vicinity of the adatom's nuclei. The analysis based on the effective Hamiltonian within the orbital-angular-momentum approach to the Rashba effect indicates that the observed spin splitting originates directly from the atomic spin-orbit coupling, with the orbital angular momentum unquenched due to broken inversion symmetry.