论文标题
扭曲的双层石墨烯中复合费米的量子异常霍尔绝缘子
Quantum anomalous Hall insulator of composite fermions in twisted bilayer graphene
论文作者
论文摘要
摘要我们从理论上研究了扭曲的双层石墨烯（TBG）系统中复合费米子（CFS）的量子异常霍尔绝缘子（QAHI）的实现。我们表明，TBG中的Moiré模式不仅能够提供相称的Moiré超晶格，而且还可以提供实现所需的可调有效的周期性潜力，而无需像常规GAAS系统那样强加其他上层建筑。这些使TBG成为实现CFS Qahi的理想平台。我们基于DIRAC CF理论建立了相对于可调实验参数的相图。我们发现，系统的拓扑特性严格取决于CFS的轨道磁化敏感性，CFS在原始Dirac CF理论中未指定。 CFS的QAHI实现实现将有助于揭示CFS的磁性并阐明该问题。
Abstract We theoretically study the realization of quantum anomalous Hall insulator (QAHI) of composite fermions (CFs) in the twisted bilayer graphene (TBG) system. We show that the moiré pattern in TBG is not only able to provide a commensurate moiré superlattice, but also a tunable effective periodic potential necessary for the realization, without the need of imposing an additional superstructure as in the conventional GaAs system. These make the TBG an ideal platform for realizing the QAHI of CFs. We establish the phase diagram with respect to tunable experimental parameters based on the Dirac CF theory. We find that the topological property of the system depends critically on the orbital magnetic susceptibility of CFs, which is not specified in the pristine Dirac CF theory. The experimental realization of QAHI of CFs would be helpful for unveiling the magnetic property of CFs and clarifying the issue.
