Ferroelectric manipulation and enhancement of Rashba spin splitting in van der Waals heterostructures

作者：Zhaofeng Liang, Jinsen Zhang, Chenqiang Hua, Yao Wang, Fei Song · 发表于：Physical review. B./Physical review. B · 年份：2024 · DOI：10.1103/physrevb.110.085110 · 被引用次数：18 · 研究领域：Topological Materials and Phenomena、Electronic and Structural Properties of Oxides、2D Materials and Applications

Ferroelectric (FE) Rashba semiconductors, a class of multifunctional materials with potential applications in spintronic devices, have attracted increasing interests recently. Herein, we employ first-principles calculations and the k\ifmmode\cdot\else\textperiodcentered\fi{}p Hamiltonian method to comprehensively investigate the Rashba effect in $MX/\ensuremath{\alpha}\text{-I}{\mathrm{n}}_{2}\mathrm{S}{\mathrm{e}}_{3}$ ($MX=\mathrm{GaTe}$ and InSe) van der Waals (vdW) heterobilayers and reveal the mechanism underlying the FE manipulation of Rashba spin splitting. Remarkably, the strength of spin splitting in the $\mathrm{GaTe}/\ensuremath{\alpha}\text{-I}{\mathrm{n}}_{2}\mathrm{S}{\mathrm{e}}_{3}$ heterobilayer has been significantly enhanced several times with respect to the intrinsic $\ensuremath{\alpha}\text{-I}{\mathrm{n}}_{2}\mathrm{S}{\mathrm{e}}_{3}$ monolayer. This enhancement is attributed to the effective interfacial electric field contributed from the strong interfacial charge transfer and mirror symmetry breaking. Furthermore, the symmetric and asymmetric $\ensuremath{\alpha}\text{-I}{\mathrm{n}}_{2}\mathrm{S}{\mathrm{e}}_{3}/\mathrm{GaTe}/\ensuremath{\alpha}\text{-I}{\mathrm{n}}_{2}\mathrm{S}{\mathrm{e}}_{3}$ sandwiched structures with four switchable states verify that Rashba spin splitting can be effectively tuned by the FE switch, and its enhancement is achievable if the mirror symmetry is not preserved. Interestingly, spin Hall conductivity can also be manip...