Giant tunable Rashba spin splitting in two-dimensional polar perovskites TlSnX3 (X = Cl, Br, I).

Abstract

The electronic structures and Rashba effect of two-dimensional polar tetragonal perovskites TlSnX3 (X = Cl, Br, I) are investigated by first-principles density functional theory, and intrinsic Rashba effects are found around the Γ point. In particular, TlSnI3 has the largest Rashba constant of 1.072 eV Å-1. Additionally, TlSnBr3 and TlSnI3 respond strongly to the applied electric field, and the electric field responsivity of TlSnI3 can reach 0.790 e Å2. Therefore, due to the large Rashba constants and strong electric field responses, these 2D polar perovskites are promising semiconductor materials with short channel lengths. The nano-scale short spin coherence length can keep the spin coherence of spin FETs, which is superior to the traditional 3D micron spin FETs, and will show a broad application prospect in the Rashba semiconductor field.