Environmentally Induced Exceptional Points in Elastodynamics
Environmentally Induced Exceptional Points in Elastodynamics
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DOI：
10.1103/physrevapplied.13.014060
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发表时间：
2020-01-29
影响因子：
4.6
通讯作者：
Kottos, T.
中科院分区：
文献类型：
--
作者：
Dominguez-Rocha, V;Thevamaran, Ramathasan;Kottos, T.
我们研究一对非厄米耦合机械振荡器中环境引起的异常点的性质。机械振荡器是由铝制成的单一各向同性弹性动力介质雕刻而成的一对支柱，由精心控制的微分损耗组成。振荡器间耦合完全源自与“环境”相关的背景模式，“环境”是结构的一部分，如果完全刚性，将在没有耦合的情况下支撑振荡器。我们根据耦合模式框架描述了有效的相互作用，其中只有一种附近的环境模式可以定性地再现异常点特征的变化。我们的实验和数值演示说明了利用环境模式控制来实施异常点简并的战略方向。潜在的应用包括新型非侵入性差动原子力显微镜和用于表面结构完整性的超灵敏传感器。
We study the nature of an environment-induced exceptional point in a non-Hermitian pair of coupled mechanical oscillators. The mechanical oscillators are a pair of pillars carved out of a single isotropic elastodynamic medium made of aluminum and consist of carefully controlled differential losses. The interoscillator coupling originates exclusively from background modes associated with the "environment," that portion of the structure which, if perfectly rigid, would support the oscillators without coupling. We describe the effective interaction in terms of a coupled-mode framework in which only one nearby environmental mode can qualitatively reproduce changes to the exceptional-point characteristics. Our experimental and numerical demonstrations illustrate strategic directions utilizing environmental mode control for the implementation of exceptional-point degeneracies. Potential applications include a new type of noninvasive differential atomic force microscopy and hypersensitive sensors for the structural integrity of surfaces.