Title: Effects of Domain Walls in Quantum Anomalous Hall Insulator/Superconductor Heterostructures Show Chinese title

Title: 量子反常霍尔绝缘体/超导体异质结构中畴壁的影响

Abstract: In a recent experiment, half-quantized longitudinal conductance plateaus (HQCPs) of height $\frac{e^2}{2h}$ have been observed in quantum anomalous Hall (QAH) insulator/superconductor heterostructure transport measurements. It was predicted that these HQCPs are signatures of chiral Majorana edge states. The HQCPs are supposed to appear in the regimes where the Hall conductance $\sigma_{xy}$ is quantized. However, experimentally, a pair of the HQCPs appear when the Hall conductance $\sigma_{xy}$ is only 80% of the quantized value when dissipative channels appear in the bulk. The dissipative channels in the bulk are expected to induce Andreev reflections and ruin the HQCPs. In this work, we explain how domain walls can cause $\sigma_{xy}$ to deviate from its quantized value and at the same time maintain the quantization of HQCPs. Our work supports the claim that the experimentally observed HQCPs are indeed caused by chiral Majorana modes in the QAH insulator/superconductor heterostructure. Show Chinese abstract

Abstract: 在最近的实验中，在量子反常霍尔（QAH）绝缘体/超导体异质结构输运测量中观察到了高度为$\frac{e^2}{2h}$的半整数量子化纵向电导平台（HQCPs）。预测这些HQCPs是手性马约拉纳边缘态的特征。HQCPs应该出现在霍尔电导$\sigma_{xy}$量化的情况下。然而，实验上，当体态中出现耗散通道时，霍尔电导$\sigma_{xy}$只达到量化值的80%，此时会出现一对HQCPs。体态中的耗散通道预计会引发安德烈夫反射并破坏HQCPs。在本工作中，我们解释了畴壁如何导致$\sigma_{xy}$偏离其量化值，同时保持HQCPs的量化。我们的工作支持实验观察到的HQCPs确实是由QAH绝缘体/超导体异质结构中的手性马约拉纳模式引起的这一说法。