Polarization tunable Rashba effect in 2D LiAlTe₂

The coexistence of polarization and the Rashba effect in ferroelectrics enables the electrical control of spin degree of freedom. Here, we explore the Rashba effect in 2D ferroelectric LiAlTe2, which has been predicted recently based on the global structure search by the particle optimization algorithm. Based on the density functional theory calculations, we have studied the electronic structures and spin textures driven by spin-orbit coupling and demonstrated a large Rashba spin splitting around the bottom of conduction bands. Further, the magnitude of the Rashba parameter is tunable by polarization switching. The physical mechanism of the Rashba effect is well analyzed within the k · p Hamiltonian model using the method of invariants. Our results add additional functionality to 2D LiAlTe2.