具有完全带隙的异质结构声子晶体的声波导特性

Characteristics of the Sonic Waveguide in a Phononic Crystal Heterostructure with a Complete Band Gap

利用正方形和三角形结构声子晶体具有范围较大完全带隙的特性,设计了新型正方形晶格和三角形晶格构成的声子晶体异质结。采用平面波展开和超原胞相结合的方法研究了该异质结的能带结构特性。给出异质结的结构和相应的能带图,分析了异质结界面传导模,研究两侧结构作横向拉开和侧向滑移时对传导模的影响,讨论这些结构的实际可行性。计算结果表明,没有任何晶格移动,该结构异质结在完全带隙中就有传导模存在,界面两侧发生相对移动时,带隙内传导模的数量及位置都发生变化。

In the present paper,a new kind of phononic crystal heterostructure formed by square and triangle lattices is proposed.The band gap structure of this phononic crystal heterostructure is investigated with supercell technique based on the plane-wave expansion method.The configuration of heterostructure and the corresponding band structures are obtained and the guide modes are analyzed.Furthermore,the influences of longitudinal sideslipping and transverse displacement of lattices on the band gap structures are discussed.It may provide a new configuration to generate guide modes.The achieved results show that the guide modes can exist in this heterostructure without any shift of lattices,and the number and positions of guide modes are influenced by the relative sideslipping.