Phys.org August 8, 2023
Understanding the interplay of band topology and electronic interactions in topological systems remains a frontier question. A team of researchers in the US (Emory University, Stanford University) predicted new interacting electronic orders emerging near higher order Van Hove singularities present in the Chern bands of the Haldane model. They classified the nature of such singularities and employed unbiased renormalization group methods that unveiled a complex landscape of electronic orders, which included ferromagnetism, density waves, and superconductivity. Importantly, they showed that repulsive interactions could 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. According to the researchers 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… read more. TECHNICAL ARTICLEÂ
(a) Lattice model. (b) Landscape of VHSs… Credit: Phys. Rev. Lett. 131, 026601, 11 July 2023