2020/09/30 by Can Shao, Eduardo V. Castro, Shijie Hu +1 · 34 citations
Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Combinatorics #Ground state #Hubbard model #Lattice (music) #Mathematics #Phase (matter) #Phase diagram #Physics #Quantum many-body systems #Quantum mechanics #Renormalization group #Superconductivity #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.103.035125
published in Physical review. B./Physical review. B 103(3) (American Physical Society) · 11 pages, 8 figures
openalex publication_date 2021/01/19 · arxiv created 2021/01/20 · arxiv updated 2021/01/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the ground-state phase diagram of the spinful extended Haldane-Hubbard model on the honeycomb lattice using an exact-diagonalization, mean-field variational approach, and further complement it with the infinite density matrix renormalization group, applied to an infinite honeycomb cylinder. This model, governed by both on-site and nearest-neighbor interactions, can result in two types of insulators with finite local order parameters, either with spin or charge ordering. Moreover, a third one, a topologically nontrivial insulator with nonlocal order, is also manifest. We test expectations of previous analyses in spinless versions asserting that once a local order parameter is formed, the topological characteristics of the ground state, associated with a finite Chern number, are no longer present, resulting in a topologically trivial wave function. Our study confirms this overall picture, and highlights how finite-size effects may result in misleading conclusions on the coexistence of finite local order parameters and nontrivial topology in this model.