The study of the spin-orbit coupling (SOC) effect is an active research field in physics and it is of great interest for materials with large Rashba spin splitting (RSS) in spintronics applications. In this report, based on first-principles calculations, we propose the heterostructure of MoS₂/Bi₂Te₃ with giant RSS duo to the lack of spatial inversion symmetry and the intrinsic electric field perpendicular to the heterostructure. Furthermore, it is found that the electronic and RSS can be tuned effectively by layers of MoS₂ and Bi₂Te₃. When the Bi₂Te₃ thickness is less than 2QL, these MoS₂/Bi₂Te₃ heterojunction systems exhibit semiconductor properties. The magnitude of the RSS in these MoS₂/Bi₂Te₃ heterojunctions changes with the thickness, and the largest band splitting is found in the (MoS₂)₁(Bi₂Te₃)₂ heterostructure with a Rashba coefficient of ~2.5 eV Å, which is a very large value among two-dimensional (2D) materials. While the interlayer distance and charge transfer remain stable at about 3.5 Å and 0.1 e, respectively. Through layer-projected band structure analysis, it is proven that the electronic states of these quantum well states (QWSs) are mainly contributed by Bi₂Te₃, while the MoS₂ layer only plays an inductive role and does not contribute to the QWSs electrons. In addition, strain only plays a minor role in the Rashba effect in the MoS₂/Bi₂Te₃ heterojunction, which is mainly caused by the breaking of the spatial inversion symmetry. The giant and tunable Rashba-type SOC of the MoS₂/Bi₂Te₃ heterostructure suggests that it is a type of promising materials for spintronic applications.

自旋轨道耦合 (SOC) 效应的研究是物理学中一个活跃的研究领域，它对自旋电子学应用中具有大 Rashba 自旋分裂 (RSS) 的材料非常感兴趣。在本报告中，基于第一性原理计算，由于缺乏空间反转对称性和垂直于异质结构的固有电场，我们提出了具有巨型 RSS的 MoS ₂ /Bi ₂ Te ₃异质结构。此外，还发现通过MoS ₂和Bi ₂ Te ₃层可以有效地调节电子和RSS 。当Bi ₂ Te ₃厚度小于2QL时，这些MoS ₂ /Bi ₂Te ₃异质结系统表现出半导体特性。这些 MoS ₂ /Bi ₂ Te ₃异质结中RSS 的大小随厚度而变化，最大的带分裂出现在 (MoS ₂ ) ₁ (Bi ₂ Te ₃ ) ₂异质结构中，Rashba 系数为~2.5 eV Å，这是二维 (2D) 材料中非常大的值。而层间距离和电荷转移分别保持稳定在 3.5 Å 和 0.1 e 左右。通过层投影能带结构分析，证明这些量子阱态（QWSs）的电子态主要由Bi ₂贡献Te ₃，而MoS ₂层仅起感应作用并且对QWSs电子没有贡献。此外，应变在MoS ₂ /Bi ₂ Te ₃异质结中的Rashba效应中只起次要作用，这主要是由空间反转对称性破坏引起的。MoS ₂ /Bi ₂ Te ₃异质结构的巨大且可调的Rashba型SOC表明它是一种有前途的自旋电子应用材料。