外尔半金属中的光子自旋霍尔效应研究

Photonic spin Hall effect is an optical effect caused by the spin-orbit interaction of light. The study of it will lead to the generation of new photonic devices and a new subject similar to spintronics —spin photonics. As a new type of topological quantum state material, Weyl semimetals have Special band structure and novel properties. We predicte that the interaction between Weyl semimetals and light will form a peculiar photonic spin Hall effect or other novel optical effects. In this project, based on quantum weak measurement technology, we investigate the photonic spin Hall effect in Weyl semimetals. On the one hand, it reveals the new characteristics, new rules and intrinsic physical mechanism of photonic spin Hall effect in Weyl semimetals. On the other hand, we establish the relationship between photonic spin Hall effect and material properties (material parameters and microstructures) of Weyl semimetals, and a simple, cheap and precise method for measuring physical parameters of Weyl semimetals is developed by using weak measurement technology. This research will expand the research of photonic spin Hall effect and Weyl semimetals, and promote the application of the basic research results of photonic spin Hall effect.

光子自旋霍尔效应是一种由光的自旋-轨道相互作用导致的光学效应，其研究会导致新型光子学器件的产生，并衍生出一门类似于自旋电子学的新学科——自旋光子学。外尔半金属作为一种新型拓扑量子态材料，具有特殊能带结构和性质，我们推测，其与光相互作用会形成奇特的光子自旋霍尔效应或者新奇的光学效应。本申请项目基于量子弱测量技术，开展对外尔半金属中的光子自旋霍尔效应的研究。一方面揭示外尔半金属中光子自旋霍尔效应的新特性、新规律、内在物理机制，另一方面，建立光子自旋霍尔效应与外尔半金属的物质特性（材料参数和微观结构）联系，并利用弱测量技术，发展一种简单、廉价、精密的外尔半金属物理参数的测量方法。该研究将拓展光子自旋霍尔效应和外尔半金属的研究，促使光子自旋霍尔效应的基础研究成果走向应用。

我们首先完整地建立了拓扑材料——外尔半金属和光子狄拉克超材料中光子自旋霍尔效应理论模型，并详细研究了理论模型中各个材料参数的改变对产生的光子自旋霍尔位移的影响。基于此理论研究，我们实现了效率显著提高的二阶光学微分运算和矢量光场在高阶邦加球上的产生和调控。其次，搭建相应的弱测量测量系统对一些特殊拓扑材料中的光子自旋霍尔效应进行观测，并不断完善实验系统，提升了测量精度。最后，基于对光子自旋霍尔效应产生的自旋位移的精确观测，在实验上实现了对二硫化钼的光学参数的精密测量，并验证了光与石墨烯相互作用的准确光学模型。