Nonvolatile Electric\nControl of Rashba Spin Splitting\nin Sb/In<sub>2</sub>Se<sub>3</sub> Heterostructure

Ferroelectric Rashba semiconductors (FRS) are highly\ndemanded for\ntheir potential capability for nonvolatile electric control of electron\nspins. An ideal FRS is characterized by a combination of room temperature\nferroelectricity and a strong Rashba effect, which has, however, been\nrarely reported. Herein, we designed a room-temperature FRS by vertically\nstacking a Sb monolayer on a room-temperature ferroelectric In<sub>2</sub>Se<sub>3</sub> monolayer. Our first-principles calculations\nreveal that the Sb/In<sub>2</sub>Se<sub>3</sub> heterostructure exhibits\na clean Rashba splitting band near the Fermi level and a strong Rashba\neffect coupled to the ferroelectric order. Switching the electric\npolarization direction enhances the Rashba effect, and the flipping\nis feasible with a low energy barrier of 22 meV. This Rashba–ferroelectricity\ncoupling effect is robust against changes of the heterostructure interfacial\ndistance and external electric fields. Such a nonvolatile electrically\ntunable Rashba effect at room temperature enables potential applications\nin next-generation data storage and logic devices operated under small\nelectrical currents.