声学零折射率超常材料的特性研究

Metamaterials have attracted wide concern for their peculiar properties which can't be found in natural materials. And optics zero-refractive-index metamaterials have received many research interests due to the feature that the phase of light wave/electromagnetic wave throughout them is essentially constant. Similarly, this feature can be found in acoustic zero-refractive-index metamaterials. However, by now, the researches on acoustic zero-refractive-index metamaterials are relatively very deficient. In response to this situation, this project focuses on a systematic and comprehensive research on acoustic zero-refractive-index metamaterials, including: on the propagation characteristic of acoustic waves in acoustic zero-refractive-index metamaterials with single-zero or double-zero parameters; on the transient waves behaviors of acoustic zero-refractive-index metamaterials using a time-dependent Green's function approach; on the Dirac cone dispersion at the Brillouin zone center in an acoustic zero-refractive-index metamaterial with double-zero parameters; on the experiment in fabricating acoustic zero-refractive-index metamaterials and applying them in acoustic devices like acoustic sources, acoustic lens and acoustic waveguides, etc. This project facilitates the generation of new concept, enlightens new application and therefore has a profound scientific meaning.

超常材料因为提供了自然材料所不具备的超常性质近年来引起了广泛的关注。这其中，零折射率光学超常材料因为光波/电磁波在其中传播时具有保持相位不变的特性而引起众多研究兴趣。类似地，声学零折射率超常材料对声波传播也具有相应的特性，但研究工作至今相对非常欠缺。鉴于此，本项目拟对声学零折射率超常材料开展系统、全面的研究，包括：研究单参数和双参数为零两类声学零折射率超常材料中声波的传播特性；用含时格林函数方法研究声学零折射率超常材料的瞬态波行为；研究双参数为零声学零折射率超常材料中位于布里渊区中心处的Dirac锥色散关系；实验制备声学零折射率超常材料，并利用其实现声源、声透镜以及声波导等多种声学器件。本项目的研究有助于提出新概念，预期新应用，具有科学意义。

本项目对声波/弹性波零折射率超常材料进行了系统深入的研究，主要包括：包含一般固体弹性缺陷的声波零折射率超常材料波导中声波的传播特性；包含固体弹性缺陷的弹性波零折射率超常材料波导中弹性横波的传播特性；一种利用两种类型的声学零折射率超常材料（单零折射率和双零折射率超材料）作为连接单元的新型声学能量分配器；一类对于纵向和横向弹性振动波都具有零折射率的人造弹性材料的弹性波传播特性；具有零折射率的人造弹性材料中球型散射体的弹性波散射特性。本项目的研究取得了一系列有意义的研究成果。到目前为止，在该基金支持下，已发表第一或通讯作者SCI论文5篇，包含Phys. Rev. Lett. 1篇，Phys. Rev.Ｂ 1篇, J. Appl. Phys. 2篇和Phys. Lett. A 1篇。