Photonic topological insulators
Photonic topological insulators
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DOI：
10.1038/nmat3520
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发表时间：
2013-03-01
期刊：
影响因子：
41.2
通讯作者：
Shvets, Gennady
中科院分区：
文献类型：
--
作者：
Khanikaev, Alexander B.;Mousavi, S. Hossein;Shvets, Gennady
在理解凝聚态物质的拓扑性质方面的最新进展导致了时间反转不变的拓扑绝缘体的发现。这些材料的一个显著和有用的特性是它们支持在其表面进行单向自旋极化传播。不幸的是，拓扑绝缘体在固态材料中很少见。使用适当设计的电磁介质(超材料)，我们从理论上演示了一种拓扑绝缘体的光子模拟。我们发现，超晶体--具有精心设计的性质的超材料超晶格--为设计拓扑非平凡的光子态提供了一个平台，类似于已被确定为凝聚态拓扑绝缘体的那些光子态。准晶体的界面支持螺旋边缘状态，这种状态表现出自旋极化的光子单向传播，对无序具有很强的抵抗力。我们的结果证明了在不施加外加磁场或破坏时间反转对称性的情况下实现单向光子输运的可能性。这种自旋极化的单向传输使奇特的自旋遮盖光子源不会相互遮挡。
Recent progress in understanding the topological properties of condensed matter has led to the discovery of time-reversal-invariant topological insulators. A remarkable and useful property of these materials is that they support unidirectional spin-polarized propagation at their surfaces. Unfortunately topological insulators are rare among solid-state materials. Using suitably designed electromagnetic media (metamaterials) we theoretically demonstrate a photonic analogue of a topological insulator. We show that metacrystals-superlattices of metamaterials with judiciously designed properties-provide a platform for designing topologically non-trivial photonic states, similar to those that have been identified for condensed-matter topological insulators. The interfaces of the metacrystals support helical edge states that exhibit spin-polarized one-way propagation of photons, robust against disorder. Our results demonstrate the possibility of attaining one-way photon transport without application of external magnetic fields or breaking of time-reversal symmetry. Such spin-polarized one-way transport enables exotic spin-cloaked photon sources that do not obscure each other.