论文标题
在存在外部磁场和颗粒孔不对称的情况下，量子异常效应的命运
Fate of Quantum Anomalous Hall Effect in the Presence of External Magnetic Fields and Particle-Hole Asymmetry
论文作者
论文摘要
量子异常大厅（QAH）效应是平等异常的缩合物质类似物，其特征是在没有外部磁场的情况下进行了量化的霍尔电导率。但是，最近已经表明，即使在存在兰道水平的情况下，QAH效应也可以与由于奇偶元异常引起的常规量子大厅（QH）效应区分开。作为这种效果的签名，我们预测了QAH和QH边缘状态的共存。在目前的工作中，我们将这些发现概括为QAH绝缘子，具有断裂的粒子对称性。特别是，我们得出了与光谱不对称的连接，这是在类似狄拉克的系统背景下产生的拓扑数量。此外，结果表明，取决于磁场方向，颗粒孔不对称增强或削弱了反向传播QH和QAH边缘状态的杂交。得出了对铁磁性拓扑绝缘子的影响，即使在外部磁场中，也为识别QAH效应的特征铺平了道路。
The quantum anomalous Hall (QAH) effect, a condensed matter analog of the parity anomaly, is characterized by a quantized Hall conductivity in the absence of an external magnetic field. However, it has been recently shown that, even in the presence of Landau levels, the QAH effect can be distinguished from the conventional quantum Hall (QH) effect due to the parity anomaly. As a signature of this effect, we predicted coexistent counterpropagating QAH and QH edge states. In the present work, we generalize these findings to QAH insulators with broken particle-hole symmetry. In particular, we derive the connection to the spectral asymmetry, which is a topological quantity arising in the context of Dirac-like systems. Moreover, it is shown that, depending on the magnetic field direction, particle-hole asymmetry strengthens or weakens the hybridization of the counterpropagating QH and QAH edge states. Implications for ferro- or paramagnetic topological insulators are derived which paves the way towards identifying signatures of the QAH effect even in external magnetic fields.
