标题： 光子弗洛凯拓扑绝缘体 显示英文标题

标题： Photonic Floquet Topological Insulators

摘要： 拓扑绝缘体是一种基本的新物质相，其显著特性是电子的导电仅发生在其表面，而非内部，并且这种导电是拓扑保护的。 拓扑保护，即电子波被无序完全不散射，可能是这种材料最引人入胜且在技术上最重要的方面：它提供了只有超导体才具有的鲁棒性。 然而，与需要低温或磁场的超导性和量子霍尔效应不同，拓扑绝缘体对无序的免疫作用发生在室温下且无需任何外部磁场。 因此，拓扑保护预计将在容错量子计算和自旋电子学中具有广泛的应用。 最近，大量的理论努力被投入到将这一概念带入光子学领域：在光学频率下实现光的拓扑保护。 除了涉及有趣的新物理现象外，光子拓扑绝缘体在光学隔离和鲁棒的光子传输方面具有应用前景。 在此，我们理论上提出并实验演示了第一个光子拓扑绝缘体：一种光子晶格，在不需要任何外部场的情况下，表现出晶格边缘的拓扑保护传输。 该系统由一系列螺旋波导组成，这些波导相互之间通过倏逝场耦合，并排列成类似石墨烯的蜂窝晶格。 波导的螺旋性导致无散射的一维边缘态，这些边缘态被拓扑保护，免受散射的影响。 显示英文摘要

摘要： The topological insulator is a fundamentally new phase of matter, with the striking property that the conduction of electrons occurs only on its surface, not within the bulk, and that conduction is topologically protected. Topological protection, the total lack of scattering of electron waves by disorder, is perhaps the most fascinating and technologically important aspect of this material: it provides robustness that is otherwise known only for superconductors. However, unlike superconductivity and the quantum Hall effect, which necessitate low temperatures or magnetic fields, the immunity to disorder of topological insulators occurs at room temperature and without any external magnetic field. For this reason, topological protection is predicted to have wide-ranging applications in fault-tolerant quantum computing and spintronics. Recently, a large theoretical effort has been directed towards bringing the concept into the domain of photonics: achieving topological protection of light at optical frequencies. Besides the interesting new physics involved, photonic topological insulators hold the promise for applications in optical isolation and robust photon transport. Here, we theoretically propose and experimentally demonstrate the first photonic topological insulator: a photonic lattice exhibiting topologically protected transport on the lattice edges, without the need for any external field. The system is composed of an array of helical waveguides, evanescently coupled to one another, and arranged in a graphene-like honeycomb lattice. The chirality of the waveguides results in scatter-free, one-way edge states that are topologically protected from scattering.