论文标题
Pi Zak阶段绝缘体中的异常介电响应
Anomalous dielectric response in insulators with the pi Zak phase
论文作者
论文摘要
在各种拓扑阶段，非平凡状态出现在系统的边界。在本文中，我们研究了由Pi Zak阶段引起的此类状态引起的异常介电响应。首先，通过使用一维Su-Schrieffer-Heeger模型，我们表明，当系统隔热并且Zak相为PI时，极化突然通过应用外部电场而升至接近E/2的大值。 Pi Zak相表示存在半填充的边缘状态，我们将这种现象归因于系统两端的边缘状态之间的转移。我们将此思想扩展到布里鲁因区域的Pi Zak阶段的二维绝缘子，并找到类似的异常介电响应。我们还表明，具有（111）表面的钻石和硅板通过AB Intio计算具有PI ZAK相，并表明这种异常响应甚至可以生存，甚至涉及涉及奇数原始表面单位细胞的表面重建。另一个具有异常介电响应的物质示例是聚氟乙烯（PTFE），与我们的理论一致，显示了通过从头算计算时 +E的极化平台。
In various topological phases, nontrivial states appear at the boundaries of the system. In this paper, we investigate anomalous dielectric response caused by such states caused by the pi Zak phase. First, by using the one-dimensional Su-Schrieffer-Heeger model, we show that, when the system is insulating and the Zak phase is pi, the polarization suddenly rises to a large value close to e/2, by application of an external electric field. The pi Zak phase indicates existence of half-filled edge states, and we attribute this phenomenon to charge transfer between the edge states at the two ends of the system. We extend this idea to two- and three-dimensional insulators with the pi Zak phase over the Brillouin zone, and find similar anomalous dielectric response. We also show that diamond and silicon slabs with (111) surfaces have the pi Zak phase by ab intio calculations, and show that this anomalous response survives even surface reconstruction involving an odd number of original surface unit cells. Another material example with an anomalous dielectric response is polytetrafluoroethylene (PTFE), showing plateaus of polarization at +e by ab initio calculation, in agreement with our theory.
