弹性波/声波超常材料(metamaterial)研究

项目名称： 弹性波/声波超常材料(metamaterial)研究

项目编号： No.10874131

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 建筑科学

项目作者： 刘正猷

作者单位： 武汉大学

项目金额： 40万元

中文摘要： 超常材料是具有有效材料参数的亚波长人工结构，特别的是，这些有效参数可以变为负数。这类材料的许多新奇性质近年来引起广泛的研究兴趣。本项目基于申请人设计出质量密度为负（SCIENCE，289，1734（2000））以及体模量和质量密度同时为负(PRL,99, 093904 (2007))的超常材料的基础，对超常材料进行了进一步的深入研究。（1）利用质量密度单负以及质量密度和体模量双负的超常材料实现了平板超透镜成像，并打破了分辨极限；（2）研究了声波在具有负参数的声学超常材料中的隧穿行为，发现与在声子晶体中不同，不仅群速度随样品厚度增加而增加，相速度也随样品厚度增加而增加；（3）设计了具有高度各向异性的声学超常材料，它是一种含有贯穿的周期性小孔或小缝阵列的刚性固体，这种超常材料可支持一种特殊的导波，利用这种导波实现了亚波长成像；（4）研究了一种两分量固体板周期性结构，发现这种不含局部共振的人工结构，具有负的质量密度，首次实现了无局部共振的负参数声学超材料；（5）研究了声波在波长及亚波长人工结构中的反常透射、电磁诱导透明（EIT）的声学类比、Zitterbewegung振荡等奇异效应。

中文关键词： 超常材料；负质量密度；遂穿；亚波长成像；反常透射

英文摘要： Metamaterials are man-made subwavelength structures being able to be described with effective material parameters,sometimes negative.Because of the unusual properties, metamaterials attract a lot of attention recently. Inspired by the successful designs of metamaterials with negative mass density (SCIENCE 289，1734（2000））and with simultaneously negative mass density and bulk modulus(PRL,99, 093904 (2007)) by the applicant and his collaborators,further investigations on metamaterials were carried out in this project. (1)Making use of the single negative and double negative metamaterials, flat superlens with limit-breaking resolution were achieved;(2)the investigations of acoustic tunneling in single negative metamaterials show that different from that in phononic crystals, not only the group velocity, the phase velocity of acoustic waves also increases with the increase of the thickness of the samples;(3)extremely anisotropic metamaterials, which are derived from stiff materials perforated with cut-through periodical holes or slits, can sustain special guiding waves, and the guding waves can be utilized to transmit evanescent waves and to form subwavelength images; (4)with a structured two-component solid plate, negative mass density was achieved without the introduction of the local resonances;and finally (5)the peculiar properties of acoustic waves in man-made structures of wavelength or subwavelength details, such as the extraordinary transmissions, the acoustic analogue of electromagnetically induced transparency (EIT), the acoustic Zitterbewegung, and so on, were investigated.

英文关键词： metamaterials; negative mass density; acoustic tunneling; subwavelength imaging; extraordinary transmission