We propose the lead sulphide (PbS) monolayer as a 2D semiconductor with a large Rashba-like spin-orbit effect controlled by the out-of-plane buckling. The buckled PbS conduction band is found to possess Rashba-like dispersion and spin texture at the M and Γ points, with large effective Rashba parameters of λ∼5eVA˚ and λ∼1eVA˚, respectively. Using a tight-binding formalism, we show that the Rashba effect originates from the very large spin-orbit interaction and the hopping term that mixes the in-plane and out-of-plane p orbitals of Pb and S atoms. The latter, which depends on the buckling angle, can be controlled by applying strain to vary the spin texture as well as the Rashba parameter at Γ and M. Our density functional theory results together with tight-binding formalism provide a unifying framework for designing Rashba monolayers and for manipulating their spin properties.
@article{arxiv.1710.09509,
title = {Two-dimensional Square Buckled Rashba Lead Chalcogenides},
author = {Paul Z. Hanakata and A. S. Rodin and Alexandra Carvalho and Harold S. Park and David K. Campbell and A. H. Castro Neto},
journal= {arXiv preprint arXiv:1710.09509},
year = {2017}
}