Accessing the exceptional points of parity-time symmetric acoustics.
Accessing the exceptional points of parity-time symmetric acoustics.
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DOI：
10.1038/ncomms11110
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发表时间：
2016-03-30
影响因子：
16.6
通讯作者：
Zhang X
中科院分区：
文献类型：
--
作者：
Shi C;Dubois M;Chen Y;Cheng L;Ramezani H;Wang Y;Zhang X
奇偶时间(PT)对称系统在例外点经历了PT精确相和断裂相之间的相变。这些PT相变对单模激光器、相干完美吸收体、隔离器和二极管的设计做出了重要贡献。然而，由于PT对称系统中所需的大多数损耗和增益材料的色散特性，在实践中很难达到这样的特异点。在这里，我们介绍了一种系统地驯服这些例外点并控制PT阶段的方法。我们的实验演示依赖于一个有源声学元件，它实现了复值电势，同时控制了结构中的多重干扰。特殊点的处理为PT对称物理在声学、光学、微波和电子学等传感、通信和成像领域的应用提供了新的途径。奇偶时间相变和例外点有助于许多部件的设计，但由于所需材料的分散性，很难获得这些部件。本文介绍了一种通过有源元件系统控制声宇称时间相变的方法。
Parity-time (PT) symmetric systems experience phase transition between PT exact and broken phases at exceptional point. These PT phase transitions contribute significantly to the design of single mode lasers, coherent perfect absorbers, isolators, and diodes. However, such exceptional points are extremely difficult to access in practice because of the dispersive behaviour of most loss and gain materials required in PT symmetric systems. Here we introduce a method to systematically tame these exceptional points and control PT phases. Our experimental demonstration hinges on an active acoustic element that realizes a complex-valued potential and simultaneously controls the multiple interference in the structure. The manipulation of exceptional points offers new routes to broaden applications for PT symmetric physics in acoustics, optics, microwaves and electronics, which are essential for sensing, communication and imaging. Parity-time phase transition and exceptional points contribute to the design of many components, but are hard to access due to the dispersive nature of the required materials. Here, the authors introduce a method to systematically control acoustic parity-time phase transition through an active element.