2004/07/31 by Jaime Merino, Hitoshi Seo, Masao Ogata · 6 citations
Materials Science · Physics and Astronomy · #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #Quantum many-body systems #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.125111
published as Phys. Rev. B 71, 125111 (2005) · 5 pages, 4 figures, to be published in Phys. Rev. B
arxiv created 2004/12/13 · openalex publication_date 2005/03/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The effect of geometrical frustration in a two-dimensional 1∕4-filled strongly correlated electron system is studied theoretically, motivated by layered organic molecular crystals. An extended Hubbard model on the square lattice is considered, with competing nearest-neighbor Coulomb interaction V, and that of next-nearest neighbor along one of the diagonals V^\ensuremath', which favor different charge ordered states. Based on exact diagonalization calculations, we find a metallic phase stabilized over a broad window at V^\ensuremath'\ensuremath∼V even for large Coulomb repulsion strengths as a result of frustrating the charge ordered states. Slightly modifying the lattice geometry relevant to the actual organic compounds does not alter the results, suggesting that this ``quantum melting'' of charge order is a robust feature of frustrated strongly correlated 1∕4-filled systems.