Rashba states situated inside the band gap of InTe/PtSe2 heterostructure

Abstract

The Rashba effect of two-dimensional (2D) materials draws significant attention because this can boost the development of novel spintronic devices. For the purpose of practical applications, the ideal Rashba states should be formed inside the band gap. However, the reports on ideal Rashba states in 2D materials are still scarce. Here, first-principles calculations are utilized to verify the Rashba spin-orbit coupling of the 2D InTe/PtSe2 van der Waals heterostructure. The occurrence of internal electric field leads to Rashba spin splitting at the valence band edge near the Γ point. These Rashba states are entirely located inside the large band gap, which helps to employ them in practical usages like spintronic devices. We also explore the influence of in-plane strains, interlayer coupling, and external electric fields on the Rashba spin splitting. The Rashba coefficients are increased linearly by the tensile strains, while the compressed strains suppress the Rashba spin splitting. The strong interlayer coupling can also promote the Rashba spin splitting. Compared to the strains, the influence of the external electric field on the Rashba effect is not noteworthy. The synchronous change of Rashba coefficients and dipole moments suggests that the internal electric field is a key factor to affect the Rashba spin splitting.