Two-dimensional Square Buckled Rashba Lead Chalcogenides

Abstract

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 $\Gamma$ points, with large effective Rashba parameters of $\lambda \sim 5$eV$\mathring{A}$ and $\lambda \sim 1$eV$\mathring{A}$, 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 $\Gamma$ 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.

References in corpus (9)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Intrinsic and Rashba Spin-orbit Interactions in Graphene Sheets
• Band Gap Engineering with Ultralarge Biaxial Strains in Suspended Monolayer MoS2
• Spin-Orbit Proximity Effect in Graphene
• Strongly spin-orbit coupled two-dimensional electron gas emerging near the surface of polar semiconductors
• Emergence of ferroelectricity and spin-valley properties in two-dimensional honeycomb binary compounds
• Crystal Field Effect Induced Topological Crystalline Insulators In Monolayer IV-VI Semiconductors
• Topological, Valleytronic, and Optical Properties of Monolayer PbS
• Orbital mapping of energy bands and the truncated spin polarization in three-dimensional Rashba semiconductors