论文部分内容阅读
A wide range of modern electronic applications are based on the charge and spin degrees of freedom(DOF)of electrons.Two-dimensional(2D)atomic crystals with honeycomb lattice,such as graphene and molybdenum disulfide MoS2 monolayer,have recently been the object of intense research activities due to the additional valley DOF of carriers that might be useful in next-generation electronics applications.Starting from these premises,by means of density functional theory calculations,we predict that several two-dimensional AB binary monolayers,where A and B atoms belong to group Ⅳ or Ⅲ-Ⅴ,are ferroelectric.Dipoles arise from the buckled structure,where the A and B ions are located on the sites of a bipartite corrugated honeycomb lattice with trigonal symmetry.We discuss the emerging valley-dependent properties and the coupling of spin and valley physics,which arise from the loss of inversion symmetry,and explore the interplay between ferroelectricity and Rashba spin-splitting phenomena.We show that valley-related properties originate mainly from the binary nature of AB monolayers,while the Rashba spin-texture developing around valleys is fully controllable and switchable by reversing the ferroelectric polarization.Our work suggests a route towards the integration of valleytronic and spintronic features in FE multivalley materials,opening unforeseen possibility in the exciting world of spintronics.