Gao Wen Sheng, Xiao Meng, Chan C T, Tam Wing Yim
Opt Lett. 2015 Nov 15;40(22):5259-62. doi: 10.1364/OL.40.005259.
For a one-dimensional (1D) periodic system with inherent mirror symmetry, the value of the geometric "Zak" phase in a bulk band is related to the sign of reflection phase for wavelengths inside the bandgaps sandwiching the bulk band. Here, we designed an interference setup which allows us to measure the reflection phase of 1D phonic crystal fabricated for the optical range; this, in turn, enabled us to determine the Zak phases of the bands. We then found interface states whose existence can be traced to the topological properties of the bandgaps and the geometric phases of the bulk bands.
对于具有固有镜面对称性的一维（1D）周期系统，体带中几何“扎克”相的值与夹在体带之间的带隙内波长的反射相符号有关。在此，我们设计了一种干涉装置，使我们能够测量为光学波段制造的一维声子晶体的反射相；这进而使我们能够确定能带的扎克相。然后，我们发现了界面态，其存在可追溯到带隙的拓扑性质和体带的几何相。
