Here, we investigate the photonic spin Hall effect in twisted bilayer graphene. The optical conductivities for several rotation angles of twisted bilayer graphene are calculated by first principles, based on which a theoretical framework is established to describe the light–matter interaction. To enhance the photonic spin Hall effect, twisted bilayer graphene is placed on a BK7 glass substrate and a Gaussian beam is launched near the Brewster angle. The spin splitting as well as Goos–Hänchen shifts are investigated, which are associated, respectively, with the imaginary and real parts of the surface conductivities of the twisted bilayer graphene. These findings provide a deeper understanding of the photonic spin Hall effect in two-dimensional materials and have potential application in characterizing bilayer graphene.

中文翻译：

---

扭曲双层石墨烯中的光子自旋霍尔效应

在这里，我们研究了扭曲双层石墨烯中的光子自旋霍尔效应。根据第一性原理计算了扭曲双层石墨烯几个旋转角的光导率，并在此基础上建立了描述光-物质相互作用的理论框架。为了增强光子自旋霍尔效应，将扭曲的双层石墨烯放置在 BK7 玻璃基板上，并在布鲁斯特角附近发射高斯光束。研究了自旋分裂以及 Goos-Hänchen 位移，它们分别与扭曲双层石墨烯的表面电导率的虚部和实部相关。这些发现提供了对二维材料中光子自旋霍尔效应的更深入理解，并在表征双层石墨烯方面具有潜在应用。