Zhang Yuqi, Wang Xiangguang, Zhang Dezhi, Fu Shufang, Zhou Sheng, Wang Xuan-Zhang
Opt Express. 2020 Jun 22;28(13):19205-19217. doi: 10.1364/OE.395594.
Three Dyakonov-like polaritons (DLPs) exist at the interface between a hyperbolic material (HM) and a covering medium (CM). Each DLP is a hybridized-polarization surface polariton composed of two evanescent waves on both sides of the interface. We investigated their spin and angular momentum. We analytically found that any DLP carries two spins producing mutually orthogonal spin angular-momentum (SAM) components. The spins and angular-momentum have different features on both sides of the interface, and further differences among the three DLPs are very obvious. For the interface structure formed by hexagonal boron nitride (hBN) and air, the SAM mainly distributes in the air for DLP-I, the SAM is approximately transverse to the propagating direction for DLP-II, and it is surprisingly large in the hBN for DLP-III and can reach several ten times that in the usual situation. There is the spin-k locking for every DLP, but the spin-k locking is different for different DLPs. These properties do not exist for traditional surface polaritons or ordinary evanescent waves. The above unique results can support some potential applications in the fields of nano- and micro-photonics, optoelectronics and mechanics, as well as relevant technologies.
在双曲材料（HM）与覆盖介质（CM）的界面处存在三种类狄亚科诺夫极化激元（DLP）。每个DLP都是一种由界面两侧的两个倏逝波组成的杂化极化表面极化激元。我们研究了它们的自旋和角动量。我们通过分析发现，任何一个DLP都携带两个自旋，产生相互正交的自旋角动量（SAM）分量。自旋和角动量在界面两侧具有不同的特征，并且三种DLP之间的进一步差异非常明显。对于由六方氮化硼（hBN）和空气形成的界面结构，对于DLP - I，SAM主要分布在空气中；对于DLP - II，SAM大致垂直于传播方向；而对于DLP - III，其在hBN中出奇地大，可达通常情况下的几十倍。每个DLP都存在自旋 - k锁定，但不同的DLP其自旋 - k锁定情况不同。传统表面极化激元或普通倏逝波不存在这些特性。上述独特结果可支持在纳米和微光子学、光电子学和力学以及相关技术领域的一些潜在应用。
