磁性绝缘体和石墨烯等二维材料的复杂异质结构及其界面效应的基础研究

The high integration of micro and nano-devices have gradually become the subject of microelectronics research, so that low dimensional materials and nano-scale interfacial effects catch people’s attention at the same time. This project aims at the fabrication of high quality thin films and the transfer of 2D materials in order to study the interfacial effect of complex heterostructures based on magnetic insulators and 2D materials like graphene. Pulsed laser deposition is used to fabricate high quality epitaxial magnetic insulator films, and then 2D materials like graphene is transferred onto the surface of magnetic insulator. The proximity effect at the interface will be explored, characterized and studied on the magnetic and electrical transport properties at the microscopic-nanoscopic scale. Meanwhile, the change of the surface energy band structure is characterized by the angle-resolved photoemission spectroscopy. The influence brought by proximity effect in the properties of graphene and other 2D materials can be uncovered. On this basis, the molecular beam epitaxy technique will be used to insert a layer of discontinuous strong spin-orbit-coupling metal at the interface between graphene and magnetic insulator. Finally, more novel physical phenomenon can be observed in graphene. This project will provide the experimental reference and solutions for the future applications of graphene and other 2D materials in spintronic devices.

高集成度的微纳器件逐渐成为当前微电子科学研究的主题，低维材料以及纳米尺度的界面效应越来越引起学者们的关注。本项目面向高质量薄膜的生长以及二维材料的转移技术，开展基于磁性绝缘体和石墨烯等二维材料的复杂异质结构及其界面效应的研究。拟采用脉冲激光沉积技术生长高质量的外延磁性绝缘体薄膜，并在其上转移石墨烯等二维材料，利用界面处产生的邻近效应，从微观纳米尺度探测、表征并研究石墨烯等二维材料磁学以及电学输运性能，同时使用角分辨光电子能谱观测其表面能带结构的变化，从而探究邻近效应对于石墨烯等二维材料性能的影响机制。在此基础之上，对于石墨烯与磁性绝缘体的异质结构，采取在界面处运用分子束外延技术插入一层非连续的强自旋轨道耦合的金属的方法来增强石墨烯的自旋轨道耦合强度，最终在石墨烯中实现更多的新奇物理现象，为今后石墨烯等二维材料在自旋电子器件方面的应用提供实验参考及解决方案。

研究随着近年来电子行业的飞速发展，对于各种器件尺寸的要求越来越高，传统的三维材料器件也随着尺度的减小而出现各种负效应，低维材料以及纳米尺度的界面效应越来越引起学者们的关注。本项目面向高质量薄膜的生长以及二维材料的转移技术，开展基于磁性绝缘体和石墨烯等二维材料的复杂异质结构及其界面效应的研究。我们实现了高质量外延磁性薄膜Y3Fe5O12、Tm3Fe5O12以及Co2FeAl等的成功制备，取得了重大的科研进展同时也为界面磁邻近效应的研究提供多种候选磁性薄膜材料。成功搭建石墨烯/Pt/YIG的异质结构，对其中的反常霍尔效应进行研究，说明YIG中的磁性通过磁邻近效应成功影响到了石墨烯的输运性质。同时，完成ZrSiS、ZrTe5等多种拓扑材料以及新型二维半导体材料的高质量生长制备与性能测试工作。并对多种磁性异质结构中的超快动力学以及相关界面效应进行研究。为今后石墨烯等二维材料在自旋电子器件方面的应用以及相关复杂异质结构界面效应的研究提供实验参考及解决方案。