Emergence of the Chern Supermetal and Pair-Density Wave through Higher-Order Van Hove Singularities in the Haldane-Hubbard Model

Pedro Castro, Daniel Shaffer, Yi-Ming Wu, and Luiz H. Santos

Phys. Rev. Lett. 131, 026601 – Published 11 July 2023

Abstract

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.

Received 27 March 2023
Accepted 12 June 2023

DOI:https://doi.org/10.1103/PhysRevLett.131.026601

Physics Subject Headings (PhySH)

Density of states Electronic structure Topological phases of matter

2-dimensional systems Strongly correlated systems Topological materials Unconventional superconductors

Hubbard model Lattice models in condensed matter Quantum field theory Renormalization group Symmetries in condensed matter

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Pedro Castro¹, Daniel Shaffer¹, Yi-Ming Wu², and Luiz H. Santos¹

¹Department of Physics, Emory University, 400 Dowman Drive, Atlanta, Georgia 30322, USA
²Stanford Institute for Theoretical Physics, Stanford University, Stanford, California 94305, USA