Collaborative Research: Engineering Exceptional Points for Sound Control with Non-Hermitian Acoustic Metasurfaces

合作研究：利用非厄米特声学超表面设计声音控制的特殊点

• 批准号: 1951221
• 负责人: Yun Jing
• 金额: $ 34.36万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1951221&HistoricalAwards=false
• 关键词: Collaborative; Research; Engineering; Exceptional; Points

This project focuses on creating a new class of non-Hermitian diffractive acoustic metasurfaces. Acoustic metasurfaces are thin artificial materials that can control sound waves. These two-dimensional materials are empowered with extraordinary control over the reflected and transmitted sound. This research will establish analogies between non-Hermitian quantum mechanics and acoustics, resulting in a paradigm shift in the design strategies for acoustic metasurfaces. The project will broadly advance the field of acoustic metasurfaces through discovering new mechanisms for designing materials with novel functionalities, which will have applications in noise control, architectural acoustics, and communication. The outcome of this research will also encourage future fundamental research where acoustics could serve as a platform to materialize quantum mechanics concepts. The research activities will involve undergraduate students, as well as students from under-represented groups, and will enable innovative educational activities. Non-Hermitian systems possess entirely real-valued energy spectra below a parity-time symmetry breaking threshold, which is referred to as its exceptional point. Here, the system undergoes a dramatic phase change with two or more eigenvalues and their corresponding eigenvectors coalescing. While physically this implies that the system would exhibit exotic wave functionalities, attaining an exceptional point requires the judicious tailoring of the system’s imaginary parts. The research team here, marries non-Hermitian physics with acoustic metasurfaces and seeks to develop fundamentally new designs that exploit the ubiquitous dissipation in the metasurface micro-structure. The project will examine the scattering matrices of non-Hermitian diffractive metasurfaces in order to establish frameworks that link exceptional points of a certain number and order to their corresponding scattering matrices. Methods for tailoring the loss in metasurface building blocks in a controllable manner will be theoretically investigated and mechanisms behind the overall diffraction behavior will be studied via classical acoustic theories. At last, the team will design, fabricate and experimentally demonstrate new acoustic devices that harness intrinsic losses, such as unidirectional sound diffusers.  This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目的重点是创建一类新的非厄米衍射声学元表面。声学超表面是一种可以控制声波的薄人工材料。这些二维材料被赋予了对反射和透射声音的非凡控制。这项研究将建立非厄米量子力学和声学之间的类比，从而导致声学超颖表面设计策略的范式转变。该项目将通过发现设计具有新功能的材料的新机制来广泛推进声学超表面领域，这些材料将在噪声控制，建筑声学和通信中应用。这项研究的结果也将鼓励未来的基础研究，其中声学可以作为实现量子力学概念的平台。研究活动将涉及本科生，以及来自代表性不足群体的学生，并将使创新的教育活动。非厄米系统在宇称时间对称性破缺阈值以下具有完全实值的能谱，这被称为其例外点。在这里，系统经历了一个戏剧性的相位变化，两个或更多的本征值和它们相应的本征向量合并。虽然物理上这意味着系统会表现出奇异的波函数，但要达到一个例外点，需要明智地调整系统的虚部。这里的研究团队将非埃尔米特物理学与声学元表面结合起来，并寻求开发全新的设计，利用元表面微结构中无处不在的耗散。该项目将研究非厄米衍射元表面的散射矩阵，以建立将特定数量和顺序的例外点与其相应的散射矩阵联系起来的框架。将从理论上研究以可控方式定制超颖表面构建块中的损耗的方法，并通过经典声学理论研究整体衍射行为背后的机制。最后，该团队将设计、制造和实验演示利用固有损失的新声学设备，例如单向声音扩散器。  该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

项目成果

Nonreciprocal coupling in space-time modulated systems at exceptional points

• DOI: 10.1103/physrevb.105.l100304
• 发表时间: 2022-03
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Junfei Li;Yun Jing;S. Cummer

Tailoring Structure‐Borne Sound through Bandgap Engineering in Phononic Crystals and Metamaterials: A Comprehensive Review

• DOI: 10.1002/adfm.202206309
• 发表时间: 2022-07
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: M. Oudich;N. J. Gerard;Yuanchen Deng;Yun Jing

Observation of Degenerate Zero-Energy Topological States at Disclinations in an Acoustic Lattice

• DOI: 10.1103/physrevlett.128.174301
• 发表时间: 2022-04-26
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Deng, Yuanchen;Benalcazar, Wladimir A.;Jing, Yun
• 通讯作者: Jing, Yun