论文标题
范德华的直接带隙和强大的rashba效应INSE和SB单层异质结构
Direct band gap and strong Rashba effect in van der Waals heterostructures of InSe and Sb single layers
论文作者
论文摘要
通过堆叠不同类型的2D材料而形成的范德华异质结构正在吸引由于新的新兴物理特性（例如Interlayer Incecitons）引起的越来越多的关注。最近合成的原子稀薄的硒化（INSE）和锑（SB）单独地表现出有趣的电子特性，例如前者中的高电子迁移率，而后者的高孔迁移率。在这项工作中，我们介绍了对由INSE和SB单层组成的超薄双层异质结构的稳定性和电子特性的第一原告研究。计算出的电子带结构揭示了INSE/SB异质结构的直接带隙半导体性质，独立于堆叠模式。考虑到自旋轨道耦合，我们发现在传统带的底部发现了一个大的Rashba旋转分裂，该旋转带源自原子自旋轨道耦合，与异质结构中的对称性断裂。可以通过施加平面内双轴应变或平面外部电场来调节RashBA自旋分裂的强度。在INSE/SB双层异质结构中，大型Rashba自旋分裂的存在与合适的带隙，使它们成为自旋场效应晶体管和光电设备应用的有前途的候选者。
Van der Waals heterostructures formed by stacking different types of 2D materials are attracting increasing attention due to new emergent physical properties such as interlayer excitons. Recently synthesized atomically thin indium selenide (InSe) and antimony (Sb) individually exhibit interesting electronic properties such as high electron mobility in the former and high hole mobility in the latter. In this work, we present a first-principles investigation on the stability and electronic properties of ultrathin bilayer heterostructures composed of InSe and Sb single layers. The calculated electronic band structures reveal a direct band gap semiconducting nature of the InSe/Sb heterostructures independent of stacking pattern. Taking spin-orbit coupling into account, we find a large Rashba spin splitting at the bottom of conduction band, which originates from the atomic spin-orbit coupling with the symmetry breaking in the heterostructure. The strength of the Rashba spin splitting can be tuned by applying in-plane biaxial strain or an out-of-plane external electric field. The presence of large Rashba spin splitting together with a suitable band gap in InSe/Sb bilayer heterostructures make them promising candidates for spin field-effect transistor and optoelectronic device applications.
