论文标题
自发量子异常霍尔绝缘子中的激子带拓扑：应用于扭曲的双层石墨烯
Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene
论文作者
论文摘要
我们发现相关量子异常霍尔（QAH）绝缘子的中性粒子孔对激发的拓扑特征，其大约平坦的传导和价带具有相等且相反的非零Chern数量。使用确切的可解决模型，我们表明，底层拓扑会影响粒子孔结合状态的质量中心和相对运动。这导致形成拓扑激子带的特征，其特征与分散体和浆果曲率的不均匀性具有稳健性。我们将这些想法应用于最近报告的破碎对称性自发的QAH绝缘子中的底物对齐的魔术角扭转双层石墨烯。
We uncover topological features of neutral particle-hole pair excitations of correlated quantum anomalous Hall (QAH) insulators whose approximately flat conduction and valence bands have equal and opposite non-zero Chern number. Using an exactly solvable model we show that the underlying band topology affects both the center-of-mass and relative motion of particle-hole bound states. This leads to the formation of topological exciton bands whose features are robust to nonuniformity of both the dispersion and the Berry curvature. We apply these ideas to recently-reported broken-symmetry spontaneous QAH insulators in substrate aligned magic-angle twisted bilayer graphene.
