论文标题
拓扑模型中分数电荷的运输测量
Transport measurement of fractional charges in topological models
论文作者
论文摘要
冷凝物质系统中的静态拓扑分数电荷（TFC）与谱带拓扑有关，因此在拓扑量子计算中具有潜在的应用。但是，电子系统中这些TFC的实验测量非常具有挑战性。我们提出了一种电子传输测量方案，即可以通过与所测量的拓扑系统结合的量子点从差分电导率中提取电荷量和TFC的空间分布。对于一维Su-Schrieffer-Heeger（SSH）型号，可以验证TFC的$ E/2 $电荷及其分布。我们还表明，打破与TFC相关的某些对称性的Anderson疾病效应在高维系统中很重要，而对一维SSH链的影响很小。但是，我们的测量方案仍然可以很好地适用于特定的高阶拓扑绝缘材料，例如，即使在存在疾病效应的情况下，呼吸kagome模型中的$ 2E/3 $ TFC也可以得到确认。
The static topological fractional charge (TFC) in condensed matter systems is related to the band topology and thus has potential applications in topological quantum computation. However, the experimental measurement of these TFCs in electronic systems is quite challenging. We propose an electronic transport measurement scheme that both the charge amount and the spatial distribution of the TFC can be extracted from the differential conductance through a quantum dot coupled to the topological system being measured. For one-dimensional Su-Schrieffer-Heeger (SSH) model, both the $e/2$ charge of the TFC and its distribution can be verified. We also show that the Anderson disorder effect, which breaks certain symmetry related to the TFC, is significant in higher-dimensional systems while has little effect on the one-dimensional SSH chain. Nonetheless, our measurement scheme can still work well for specific higher-order topological insulator materials, for instance, the $2e/3$ TFC in the breathing kagome model could be confirmed even in the presence of disorder effect.
