Acoustic spinning fibers: A new avenue towards airborne nonreciprocal waveguiding
ORAL
Abstract
Metamaterials with time-varying or moving components represent a paradigm shift in the way the interaction between acoustic (or optical) waves and material is thought of. In particular, spinning meta-atoms or scatterers may result in intriguing applications such as the intrinsic torque, negative radiation force (acoustic tweezers) [M. Farhat, et al. PRB(L) 104, L060104 (2021); M. Farhat, et al. APL In Press (2022)], or even novel invisibility cloaking devices [M. Farhat, et al. PRB 101, 174111 (2020)]. Interestingly, airborne acoustic waveguides and particularly the acoustic fiber still remain a challenging goal due to the lack of materials with speed of sound lower than air. In this talk, we report a radically novel approach for acoustic waveguiding, which relies solely on spinning air, i.e., without material modulation. Our proposal results in the acoustic analogue of optical fibers, that we coin here acoustic spinning fiber (ASF). Our findings show that this ASF is not only tunable, but also unidirectional [M. Farhat, et al. PRL Submitted (2022)], as spinning here acts as the counterpart of Zeeman effect. This may lead to several applications in acoustic metamaterials and sound-based communication.
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Publication: M. Farhat, S. Guenneau, A. Alù, and Y. Wu, "Scattering Cancellation Technique for Acoustic Spinning Objects," Physical Review B 101, 174111(2020).<br><br>M. Farhat, P.-Y. Chen, M. Amin, A. Alu, and Y. Wu, "Transverse Acoustic Spin and Torque from Pure Spinning of Objects," Physical Review B (Letter) 104, L060104 (2021).<br><br>M. Farhat, S. Guenneau, P.-Y. Chen, and Y. Wu, "Scattering Properties of Acoustic Beams off Spinning Objects: Induced Radiation Force and Torque," Applied Physics Letters, In Press (2022).<br><br>M. Farhat, P.-Y. Chen, and Y. Wu, "Sound Waveguiding by Spinning: An Avenue towards Unidirectional Acoustic Spinning Fibers," Physical Review Letters, To Be Submitted (2022).
