Topologically robust sound propagation in an angular-momentum-biased graphene-like resonator lattice.
Topologically robust sound propagation in an angular-momentum-biased graphene-like resonator lattice.
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DOI：
10.1038/ncomms9260
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发表时间：
2015-10-06
影响因子：
16.6
通讯作者：
Alù A
中科院分区：
文献类型：
--
作者：
Khanikaev AB;Fleury R;Mousavi SH;Alù A
拓扑绝缘体不允许在体中传导，但它们支持边缘模式，该边缘模式仅在一个方向上沿着边界沿着行进，该方向由所携带的电子自旋确定，具有对缺陷和无序的固有鲁棒性。拓扑绝缘体激发了光子学和光学中的类似物，其中在拓扑保护的二维材料中实现单向边缘传播，打破了具有磁偏置的时间反演对称性。在这里，我们引入了经典声学中的拓扑序的概念，在适当设计的谐振器晶格中实现了稳健的拓扑保护和声音的单向边缘传播，该谐振器晶格偏置有角动量，形成了磁偏置石墨烯层的声学模拟。扩展的概念的声学非互易循环器的基础上的角动量偏置，时间反转对称性被打破，在这里使用温和的旋转运动的空气中的每个元素的晶格，这需要的作用，电子自旋在确定模式的边缘传播的方向。声音的拓扑顺序在很大程度上还未被探索。在这里，Khanikaev等人在经典声学中引入了拓扑序的概念，在适当设计的谐振器晶格中实现了稳健的拓扑保护和声音的单向边缘传播，从而扩展了定制声波的能力。
Topological insulators do not allow conduction in the bulk, yet they support edge modes that travel along the boundary only in one direction, determined by the carried electron spin, with inherent robustness to defects and disorder. Topological insulators have inspired analogues in photonics and optics, in which one-way edge propagation in topologically protected two-dimensional materials is achieved breaking time-reversal symmetry with a magnetic bias. Here, we introduce the concept of topological order in classical acoustics, realizing robust topological protection and one-way edge propagation of sound in a suitably designed resonator lattice biased with angular momentum, forming the acoustic analogue of a magnetically biased graphene layer. Extending the concept of an acoustic nonreciprocal circulator based on angular-momentum bias, time-reversal symmetry is broken here using moderate rotational motion of air within each element of the lattice, which takes the role of the electron spin in determining the direction of modal edge propagation. Topological order for sound remains largely unexplored. Here, Khanikaev et al. introduce the concept of topological order in classical acoustics, realizing robust topological protection and one-way edge propagation of sound in a suitably designed resonator lattice, thus expanding the ability to tailor acoustic waves.