2003/01/14 by Makoto Kuwabara, Hitoshi Seo, Masao Ogata
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1143/jpsj.72.225
published as J. Phys. Soc. Jpn. 72, 225 (2003) · 8 pages, 3 pages, to be published in J. Phys. Soc. Jpn., Vol. 72 No. 2
arxiv created 2003/01/14 · arxiv updated 2009/11/30
The electronic properties of quarter-filled organic materials showing spin-Peierls transition are investigated theoretically. By studying the one-dimensional extended Peierls-Hubbard model analytically as well as numerically, we find that there is a competition between two different spin-Peierls states due to the tetramized lattice distortion in the strongly correlated regime. One is accompanied by lattice dimerization which can be interpreted as a spontaneous Mott insulator, while the other shows the existence of charge order of Wigner crystal-type. Results of numerical density matrix renormalization group computations on sufficiently large system sizes show that the latter is stabilized in the ground state when both the on-site and the inter-site Coulomb interactions are large.