量子阱中电场引起的重-轻空穴耦合和新型Rashba自旋-轨道耦合效应的理论研究

自旋-轨道耦合效应是低维半导体自旋电子学研究的重要内容之一。传统半导体量子阱中空穴态因具有自旋-轨道相互作用强、自旋态寿命长的特点吸引了广泛的研究兴趣。目前在空穴态自旋劈裂的研究方面已经有不少工作，然而这些研究忽略了外加电场引起的重-轻空穴耦合。本项目拟结合经验赝势理论计算，构建考虑重-轻空穴耦合的量子阱中空穴自旋劈裂模型，全面深入地理解重-轻空穴耦合机制和其对自旋劈裂的相对贡献；探讨不同组分、应变、生长方向等手段对量子阱中重-轻耦合强度进而自旋劈裂大小的影响；探索潜在的自旋半导体器件应用机理。通过该项目的基础研究，可以发现和认识新型Rashba自旋-轨道耦合效应，为未来信息技术中高速、低耗的新型半导体器件设计提供物理基础。

Spin-orbit coupling in low-dimensional semiconductor materials is one of the fascinating subjects of Spintronics. The hole states in conventional semiconductor quantum wells have attracted great attention due to their distinct physical properties such as strong spin-orbit coupling, long spin lifetime and so on. Despite much effort has been devoted to the study of hole spin splitting, the heavy-hole (HH) and light-hole (LH) coupling induced by electric field has been ignored. In this project, based on atomistic pseudopotential method combined with effective Hamiltonian, we will explore mechanisms of HH-LH coupling hence its contributions to spin splitting, and then study the effects of composition, the direction of crystal growth and strain on this coupling as well as splitting. Finally, we shall design the potential application principle to achieve engineering the spin of degree in quantum wells. Our research will provide a new path toward novel Rashba spin-orbital coupling stemming from HH-LH coupling, and discover their rich intriguing properties to promote the great potential for applications in Spintronics.