2017/04/07 by Owen Myers, C. M. Herdman, Chris M. Herdman · 4 citations
Mathematics · Physics and Astronomy · #Combinatorics #Dimer #Ground state #Hamiltonian (control theory) #Ising model #Mathematics #Pentamer #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Square lattice #Symmetry protected topological order #Topological degeneracy #Topological order #Topology (electrical circuits) #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.96.174434
published in Physical review. B./Physical review. B 96(17) (American Physical Society) · 12 pages, 12 figures
arxiv created 2017/04/07 · openalex publication_date 2017/11/27 · arxiv updated 2017/12/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We introduce the quantum dimer-pentamer model (QDPM) on the square lattice. This model is a generalization of the square-lattice quantum dimer model as its configuration space comprises fully packed hard-core dimer coverings as well as dimer configurations containing pentamers, where four dimers touch a vertex. Thus in the QDPM, the fully packed, hard-core constraint of the quantum dimer model is relaxed such that the local dimer number at each vertex is fixed modulo 3, resulting in an exact local Z3 gauge symmetry. We construct a local Hamiltonian for which the Rokhsar-Kivelson (RK) equal superposition state is the exact ground state and has a ninefold topological degeneracy on the torus. Using Monte Carlo calculations, we find no spontaneous symmetry breaking in the RK wave function and that its dimer-dimer correlation function decays exponentially. By doping the QDPM RK state with a pair of monomers, we demonstrate that Z3 electric charges are deconfined. Additionally, we introduce a Z3 magnetic string operator that we find decays exponentially and shows no signatures of magnetic vortex condensation. These numerical results suggest that the ground state of the QDPM is a dimer liquid with Z3 topological order.