Rashba效应导致的二维材料/YIG异质结构中的自旋霍尔磁电阻的研究

自旋霍尔磁电阻是一种非平衡邻近效应，一般存在于非磁/铁磁绝缘体异质结构中，由非磁材料中自旋霍尔效应和逆自旋霍尔效应共同作用产生的新型磁电阻效应。自旋霍尔磁电阻理论使铁磁绝缘体的应用成为可能，并可被用于非侵入地获取非磁层的某些基本参数，如自旋霍尔角，自旋扩散长度等，是目前自旋电子学领域的研究热点。目前自旋霍尔磁电阻的研究主要集中在重金属/铁磁绝缘体体系中，其成因是重金属层的本征自旋-轨道耦合（SOC）效应。然而，自旋霍尔磁电阻是一种典型的界面效应，界面处的Rashba自旋-轨道耦合效应也会对磁电阻产生重要影响。如何区分本征SOC效应和Rashba效应仍是研究的难点。本申请项目选择具有强Rashba效应和弱本征SOC效应的二维材料，如二维过渡金属硫化物、石墨烯等，利用物理和化学方法制备微结构、尺寸可控的二维材料/YIG异质结构，系统研究微结构、界面、温度、电场和磁场对其自旋霍尔磁电阻调控的规律

Spin Hall magnetoresistance is a kind of non-equilibrium proximity effect, which is usually found in non-magnetic/ferromagnetic insulator heterostructures. It is a new type of magnetoresistance effect caused by spin Hall effect and inverse spin Hall effect in non-magnetic materials. spin Hall magnetoresistance theory makes the application of ferromagnetic insulators possible, and can be used to non-invasively acquire some basic parameters of non-magnetic layers, such as spin Hall angle, spin diffusion length, etc. it is the research hotspots in the field of spintronics. At present, the research of spin Hall magnetoresistance is mainly concentrated in the heavy metal/ferromagnetic insulator system, which is due to the intrinsic spin-orbit coupling (SOC) effect of the heavy metal layer. However, the spin Hall magnetoresistance is a typical interfacial effect, and the Rashba spin-orbit coupling effect at the interface also has an important effect on the magnetoresistance. How to distinguish between intrinsic SOC effect and Rashba effect is still a difficult point of research. This application selects two-dimensional materials with strong Rashba effect and weak intrinsic SOC effect, such as two-dimensional transition metal sulfides, graphene. The microstructures, size-controlled two-dimensional materials/YIG heterostructure will be prepared using physical and chemical methods. Systematically study the laws governing the spin Hall magnetoresistance of microstructure, interface, temperature, electric field and magnetic field, and reveal the influence mechanism of Rashba effect on spin Hall magnetoresistance.