Switchable S = 1/2 and J = 1/2 Rashba bands in ferroelectric halide perovskites

Abstract

Significance Manipulation of electron spins is an important research subject to achieve breakthroughs in current electronics. The Rashba effect is the spin energy level splitting due to broken inversion symmetry and spin–orbit coupling, and the controllability of Rashba splitting is crucial to spin manipulation. Here, we report a theoretical investigation of Rashba band splitting in ferroelectric halide perovskite materials. Since the polarization direction in ferroelectric materials can be switched by external electric fields, Rashba splitting can be controlled conveniently in these materials. Interestingly, ferroelctric polarizations give rise to two distinct Rashba bands of contrasting orbital and spin characters. Taking advantage of the unique band characteristics, these materials prove promising candidates for the switchable Rashba effect.