研究了二维复式声子晶体中基元配置对其声学能带结构的影响,发现当声子晶体的基元配置改变时,声子晶体的不可约布里渊区也会改变,而且部分能带的极值不再在高对称线上.特别地,在某些基元配置下,不可约布里渊区扩大为整个第一布里渊区.因此,对于对称性较高的复式晶格声子晶体,可用通常的方法得到能带结构,而对于对称性较低的复式晶格结构声子晶体,只有采用对整个第一布里渊区进行研究的方法,才能获得可信的能带结构及带隙.
The effect of basis configuration on acoustic band structure in two-dimensional complex phononic crystals (PCs) was investigated. We found that when the basis configuration was changed, the irreducible Brillouin zone (BZ) of PCs might be changed too,and part of band extrema were no longer on the high-symmetry lines. In particular,the PCs with some basis configurations were forced to render the whole first BZ irreducible. Therefore,besides the high symmetrical PCs,only by throughout investigation of the BZ can we obtain the authentic band structures and band gaps for the lower symmetrical PCs with complex crystal lattice.