Charge Gap, Charge Susceptibility and Spin Correlationin the Hubbard Model on a Square Lattice

作者：Nobuo Furukawa, Masatoshi Imada · 发表于：Journal of the Physical Society of Japan · 年份：1991 · DOI：10.1143/jpsj.60.3604 · 被引用次数：63 · 研究领域：Physics of Superconductivity and Magnetism、Quantum and electron transport phenomena、Quantum many-body systems

Quantum Monte Carlo study of the Hubbard model on a square lattice in the ground state is reported. For the on-site interaction U =4 scaled by the transfer, the charge excitation gap at the half-filling is estimated to be Δ c =0.58±0.08. Near half-filling, the charge compressibility κ follows the form κ∝δ -1 for the doping concentration δ, indicating a divergent behavior as the system approaches half-filling, while κ=0 at the half-filling. The incommensurate spin correlation length ξ scales as ξ∝1/\(\sqrt{\delta}\).