不同填充率时三组元声子晶体缺陷态

运用基于平面波的超元胞方法,研究作为缺陷引入第三组元材料(四氯化碳)对二维二组元声子晶体(水/水银)带结构的影响。结果表明:当缺陷柱填充率发生变化时,原带隙的位置、宽度变化不大;缺陷带频率主要受第三组元材料物性参数的影响;当正常插入体填充率发生变化时,原带隙的位置、宽度都发生了改变,同时也影响缺陷带的出现,且这些缺陷态都是局域化的。因此,在具有宽带隙的二组元体系中引入适当的第三组元线缺陷,让缺陷带频率落在二组元体系的带隙中,就可以形成特殊的波导态。声子晶体的这一特性对于声波/弹性波的传播和新的声学应用具有重要意义。

Defect States in Three-Component Phononic Crystal by Different Filling Fraction

By means of the supercell＇plane wave method, investigated the effect of the third component material as the introduced defect on the band structure of two-dimension two-component phononic crystal （PC）. It shows that： when the filling fraction of defect rods changes, defect bands can appear in the primary band gap whose position and width had a minor change; the frequency of the defect states/bands are mainly affected by the third material＇ s physical parameters; When the filling fraction of normal rods changes, defect bands appear in the primary band gap whose position and width had also a major change, and all the defect states are localization. Therefore, adding proper third material as linear defects to the two- component system with wider band gap where defect bands will fall into, some special filter guided states will be formed. This characteristic has a very important significance for acoustic/elastic wave propagating and new acoustic applications.