2000/07/25 by Zheng Weihong, J. Oitmaa, C. J. Hamer +2 · 37 citations
Engineering · Mathematics · Physics and Astronomy · #Condensed matter physics #Hubbard model #Magnetic confinement fusion research #Mathematics #Physics #Physics of Superconductivity and Magnetism #Superconducting Materials and Applications #Superconductivity #cond-mat.str-el
paper · pdf · doi:10.1088/0953-8984/13/3/306
published in Journal of Physics Condensed Matter 13(3), 433-448 (IOP Publishing) · 10 figures, revtex
arxiv created 2000/07/25 · openalex publication_date 2000/12/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The Hubbard model on a two-leg ladder structure has been studied by a combination of series expansions at T = 0 and the density-matrix renormalization group. We report results for the ground-state energy E 0 and spin gap Δ s at half-filling, as well as dispersion curves for one- and two-hole excitations. For small U both E 0 and Δ s show a dramatic drop near t / t ⊥ ~0.5, which becomes more gradual for larger U . This represents a crossover from a `band insulator' phase to a strongly correlated spin liquid. The various features are collected in a `phase diagram' for the model.