基于MoS2/CrI3磁性二维材料异质结界面电子自旋调控及输运特性研究

Magnetic semiconductor 2D material heterostructures highlight great potential in spintronics and valleytronics. However, the mechanism of electron spin interaction at the interface of 2D layered materials are still unclear. In the project, we propose a novel heterostructure geometry comprising atomically thin two-dimensional materials (MoS2, WSe2, graphene) and magnetic 2D semicondutors (CrI3, CrBr3). Herein, we are going to focus on investigating the manipulation and interaction of electron spin between MoS2, WSe2, graphene and CrI3, CrBr3; deeply understanding the relation between gate and bias voltage, external magnetic field and circularly polarized exciting light on the the magneto-optic Kerr effect, the valley polarization, the valley Hall effect, the anomalous Hall effect, and the magneto-resistance; investigating the mechanism of spin injection, transport and manipulation; achieving spintronic devices of Graphene/CrI3、MoS2/CrI3 and improving the development of 2D materials spintronics toward practical applications.

针对未来磁性二维材料及异质结应用于自旋电子学器件的发展前沿，解决磁性二维材料异质结界面电子自旋调控机制不清楚的难题，本项目提出基于石墨烯、单层TMDs (MoS2、WSe2)、磁性二维材料(CrI3、CrBr3)构建磁性二维材料异质结；在面外（内）电场、磁场和圆偏振光的协同作用下，重点开展石墨烯、MoS2、WSe2与CrI3、CrBr3之间电子自旋相互作用的物理机制等核心科学问题的研究；探索栅压（面外电场）、偏压（面内电场）、磁场、圆偏振光与磁光克尔效应、谷极化度、谷自旋霍尔效应、反常霍尔效应、磁阻效应等自旋电子动力学行为之间的内在联系；揭示磁性二维异质结自旋注入、输运和操控的物理机制，研发Graphene/CrI3、MoS2/CrI3等磁性二维材料异质结自旋电子学器件，推动二维材料自旋电子学器件向实用化方向迈进。

在本项目的支持下，发现了全新的非互易强磁光散射效应，正负磁场的磁光旋角高达+60o和-20o，比克尔效应2个数量级，突破了磁光效应“弱”的关键科学难题；揭示了CrI3层间反铁磁耦合行为，阐明了WSe2/CrI3、graphene/CrI3异质结中的磁近邻效应，其导致了增强的谷极化效应和塞曼劈裂效应以及磁阻效应；发明了磁性二维材料多波长磁光编码技术；揭示了能谷自旋退极化机制，发展了新型磁性Fe原子掺杂二维材料MoS2，室温能谷自旋劈裂提高了4倍，实现了室温能谷操控,突破了磁光效应室温调控“难”的关键科学难题。上述研究成果发表在Sci. Adv.、Nano Lett.、ACS Nano等期刊。