摘要
我们之前的工作表明,声学超材料中的非局部相互作用会导致极不寻常的类roton色散关系,即色散曲线存在局部极小值,与超流体液氦-4类似.然而,这种行为仅限于一个或两个声传播方向.在这里,我们设计了一种三维立方对称声学超材料,沿三个正交方向具有非局部相互作用.有限元计算表明超材料在三个正交方向具有类roton行为,但其行为远非各向同性.有限元结果与半解析模型结果吻合良好.相应的实验正在探索中,由于需要密集而复杂的三维声学管道,实验要求较高.
In our previous work,we have shown that nonlocal interactions in acoustic metamaterials can lead to highly unusual roton-like dispersion relations exhibiting a minimum of frequency versus wavenumber similar to that of superfluid Helium-4.However,this behavior was limited to only one or two propagation directions of sound.Here,we design a three-dimensional cubic-symmetry airborne acoustic metamaterial with nonlocal interactions along three orthogonal directions.By using numerical finite-element calculations,we show that the metamaterial supports roton-like behavior along all three orthogonal directions,but the behavior is far from isotropic.We compare these calculations with a simplified semi-analytical model,leading to good overall agreement.Corresponding experiments appear in reach,but are demanding due to the required dense and complex three-dimensional network of acoustic channels that connect compartments of air.
作者
王珂
陈毅
Muamer Kadic
王长国
Martin Wegener
Ke Wang;Yi Chen;Muamer Kadic;Changguo Wang;Martin Wegener(National Key Laboratory of Science and Technology on Advanced Composites in Special Environments,Harbin Institute of Technology,Harbin,150001,China;Institute of Applied Physics,Karlsruhe Institute of Technology(KIT),Karlsruhe,76128,Germany;Institute of Nanotechnology,Karlsruhe Institute of Technology(KIT),Karlsruhe,76128,Germany;Institut FEMTO-ST,UMR 6174,CNRS,Universitéde Franche-Comté,Besançon,25030,France)
基金
support by the China Scholarship Council(CSC).This research has additionally been funded by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy via the Excellence Cluster“3D Matter Made to Order”(Grant No.EXC-2082/1-390761711)
which has also been supported by the Carl Zeiss Foundation through the“Carl-Zeiss-Foundation-Focus@HEiKA”,by the State of Baden-Württemberg,and by the Karlsruhe Institute of Technology(KIT).We further acknowledge support by the Helmholtz program“Materials Systems Engineering”(MSE).Muamer Kadic is grateful for support by the EIPHI Graduate School(Grant No.ANR-17-EURE-0002)
Changguo Wang is grateful for support by the National Natural Science Foundation of China(Grant No.12172102).
