Castro Pedro, Shaffer Daniel, Wu Yi-Ming, Santos Luiz H
Department of Physics, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322, USA.
Stanford Institute for Theoretical Physics, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2023 Jul 14;131(2):026601. doi: 10.1103/PhysRevLett.131.026601.
While advances in electronic band theory have brought to light new topological systems, understanding the interplay of band topology and electronic interactions remains a frontier question. In this work, we predict new interacting electronic orders emerging near higher-order Van Hove singularities present in the Chern bands of the Haldane model. We classify the nature of such singularities and employ unbiased renormalization group methods that unveil a complex landscape of electronic orders, which include ferromagnetism, density waves, and superconductivity. Importantly, we show that repulsive interactions can stabilize the long-sought pair-density-wave state and an exotic Chern supermetal, which is a new class of non-Fermi liquid with anomalous quantum Hall response. This framework opens a new path to explore unconventional electronic phases in two-dimensional chiral bands through the interplay of band topology and higher-order Van Hove singularities.
虽然电子能带理论的进展揭示了新的拓扑系统，但理解能带拓扑与电子相互作用之间的相互关系仍然是一个前沿问题。在这项工作中，我们预测在哈代模型的陈数带中存在的高阶范霍夫奇点附近会出现新的相互作用电子序。我们对这些奇点的性质进行了分类，并采用无偏重整化群方法揭示了一个复杂的电子序图景，其中包括铁磁性、密度波和超导性。重要的是，我们表明排斥相互作用可以稳定长期以来寻找的对密度波态和一种奇异的陈数超金属，这是一类具有反常量子霍尔响应的新型非费米液体。这个框架为通过能带拓扑与高阶范霍夫奇点之间的相互作用探索二维手性带中的非常规电子相开辟了一条新途径。
