Electronics Structure of Monochalcogenide Materials MX (M = Ge, Sn and Pb; X = S and Se) Buckled Square Lattice

The electronics structure of monochalcogenide materials buckled square lattice is investigated by computation based on Density Functional Theory (DFT). The investigation shows that there is spin splitting on xy-plane at Γ point and M point as a Rashba effect. Perturbation theory k.p and symmetry group C2v used to calculate the originates of the spin splitting. The results show that there are strong Rashba splitting for materials with center atom Pb (with Rashba parameter 5~ eVA). Spin orientation displayed by spin-texture and show that there is time reversal symmetry between upper band and lower band. This condition explains that monochalcogenide materials buckled square lattice as potential candidates for spintronics devices.