An invisible acoustic sensor based on parity-time symmetry

被引:620
作者
Fleury, Romain [1 ]
Sounas, Dimitrios [1 ]
Alu, Andrea [1 ]
机构
[1] Univ Texas Austin, Dept Elect & Comp Engn, Austin, TX 78701 USA
来源
Nature Communications | 2015年 / 6卷
基金
美国国家科学基金会;
关键词
NON-HERMITIAN HAMILTONIANS;
D O I
10.1038/ncomms6905
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Sensing an incoming signal is typically associated with absorbing a portion of its energy, inherently perturbing the measurement and creating reflections and shadows. Here, in contrast, we demonstrate a non-invasive, shadow-free, invisible sensor for airborne sound waves at audible frequencies, which fully absorbs the impinging signal, without at the same time perturbing its own measurement or creating a shadow. This unique sensing device is based on the unusual scattering properties of a parity-time (PT) symmetric metamaterial device formed by a pair of electro-acoustic resonators loaded with suitably tailored non-Foster electrical circuits, constituting the acoustic equivalent of a coherent perfect absorber coupled to a coherent laser. Beyond the specific application to non-invasive sensing, our work broadly demonstrates the unique relevance of PT-symmetric metamaterials for acoustics, loss compensation and extraordinary wave manipulation.
引用
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页数:7
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