Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
Nat Commun. 2022 Dec 12;13(1):7678. doi: 10.1038/s41467-022-35447-3.
Space and guided electromagnetic waves, as widely known, are two crucial cornerstones in extensive wireless and integrated applications respectively. To harness the two cornerstones, radiative and integrated devices are usually developed in parallel based on the same physical principles. An emerging mechanism, i.e., anti-parity-time (APT) symmetry originated from non-Hermitian quantum mechanics, has led to fruitful phenomena in harnessing guided waves. However, it is still absent in harnessing space waves. Here, we propose a radiative plasmonic APT design to harness space waves, and experimentally demonstrate it with subwavelength designer-plasmonic structures. We observe two exotic phenomena unrealized previously. Rotating polarizations of incident space waves, we realize polarization-controlled APT phase transition. Tuning incidence angles, we observe multi-stage APT phase transition in higher-order APT systems, constructed by using the scalability of leaky-wave couplings. Our scheme shows promise in demonstrating novel APT physics, and constructing APT-symmetry-empowered radiative devices.
众所周知，空间波和导行电磁波分别是广泛的无线和集成应用中的两个关键基石。为了利用这两个基石，辐射和集成器件通常基于相同的物理原理并行开发。一种新兴的机制，即源于非厄米量子力学的反奇偶时间（APT）对称性，在导波的利用中产生了丰富的现象。然而，它在空间波的利用中仍然不存在。在这里，我们提出了一种辐射等离子体 APT 设计来利用空间波，并通过亚波长设计等离子体结构进行了实验验证。我们观察到了两个以前没有实现的奇异现象。我们实现了对入射空间波的偏振旋转的 APT 相位转变的偏振控制。通过调整入射角，我们在使用漏波耦合的可扩展性构建的高阶 APT 系统中观察到了多阶 APT 相变。我们的方案有望展示新颖的 APT 物理，并构建基于 APT 对称性的辐射器件。
