Sound non-reciprocity based on synthetic magnetism

Zhaoxian Chen; Zhengwei Li; Jingkai Weng; Bin Liang; Yanqing Lu; Jianchun Cheng; Andrea Alù

doi:10.1016/j.scib.2023.08.013

Sound non-reciprocity based on synthetic magnetism

Sci Bull (Beijing). 2023 Oct 15;68(19):2164-2169. doi: 10.1016/j.scib.2023.08.013. Epub 2023 Aug 9.

Authors

Zhaoxian Chen¹, Zhengwei Li², Jingkai Weng², Bin Liang³, Yanqing Lu⁴, Jianchun Cheng⁵, Andrea Alù⁶

Affiliations

¹ Collaborative Innovation Center of Advanced Microstructures, Key Laboratory of Modern Acoustics of Ministry of Education, Institute of Acoustics, Department of Physics, Nanjing University, Nanjing 210093, China; College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China.
² Collaborative Innovation Center of Advanced Microstructures, Key Laboratory of Modern Acoustics of Ministry of Education, Institute of Acoustics, Department of Physics, Nanjing University, Nanjing 210093, China.
³ Collaborative Innovation Center of Advanced Microstructures, Key Laboratory of Modern Acoustics of Ministry of Education, Institute of Acoustics, Department of Physics, Nanjing University, Nanjing 210093, China. Electronic address: liangbin@nju.edu.cn.
⁴ College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China. Electronic address: yqlu@nju.edu.cn.
⁵ Collaborative Innovation Center of Advanced Microstructures, Key Laboratory of Modern Acoustics of Ministry of Education, Institute of Acoustics, Department of Physics, Nanjing University, Nanjing 210093, China. Electronic address: jccheng@nju.edu.cn.
⁶ Photonics Initiative, Advanced Science Research Center, City University of New York, New York NY 10031, USA; Physics Program, Graduate Center, City University of New York, New York NY 10016, USA. Electronic address: aalu@gc.cuny.edu.

PMID: 37604721
DOI: 10.1016/j.scib.2023.08.013

Abstract

Synthetic magnetism has been recently realized using spatiotemporal modulation patterns, producing non-reciprocal steering of charge-neutral particles such as photons and phonons. Here, we design and experimentally demonstrate a non-reciprocal acoustic system composed of three compact cavities interlinked with both dynamic and static couplings, in which phase-correlated modulations induce a synthetic magnetic flux that breaks time-reversal symmetry. Within the rotating wave approximation, the transport properties of the system are controlled to efficiently realize large non-reciprocal acoustic transport. By optimizing the coupling strengths and modulation phases, we achieve frequency-preserved unidirectional transport with 45-dB isolation ratio and 0.85 forward transmission. Our results open to the realization of acoustic non-reciprocal technologies with high efficiency and large isolation, and offer a route towards Floquet topological insulators for sound.

Keywords: Dynamic coupling; Sound non-reciprocity; Synthetic magnetism; Time modulation.