2008/05/31 by Chia-Chen Chang, Chia‐Chen Chang, Shiwei Zhang
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Iron-based superconductors research #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.78.165101
published as Phys. Rev. B 78, 165101 (2008) · 5 pages, 5 figures. title changed, final version accepted for publication
openalex publication_date 2008/10/02 · arxiv created 2008/10/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using recent advances in auxiliary-field quantum Monte Carlo techniques and the phaseless approximation to control the sign/phase problem, we determine the equation of state in the ground state of the two-dimensional repulsive single-band Hubbard model at intermediate interactions. Shell effects are eliminated and finite-size effects are greatly reduced by boundary-condition integration. Spin-spin correlation functions and structure factors are also calculated. In lattice sizes up to 16\ifmmode×\else\texttimes\fi16, the results show signals for phase separation. Upon doping, the system separates into one phase of density n=1 (hole free) and the other at density nc (\ensuremath∼0.9). The long-range antiferromagnetic order is coupled to this process and is lost below nc.