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Antiferromagnetic Phases of One-Dimensional Quarter-Filled Organic Conductors

Hitoshi Seo·Hidetoshi Fukuyama
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Abstract

The magnetic structure of antiferromagnetically ordered phases of quasi-one-dimensional organic conductors is studied theoretically at absolute zero based on the mean field approximation to the quarter-filled band with on-site and nearest-neighbor Coulomb interaction. The differences in magnetic properties between the antiferromagnetic phase of (TMTTF)$_2$X and the spin density wave phase in (TMTSF)$_2$X are seen to be due to a varying degrees of roles played by the on-site Coulomb interaction. The nearest-neighbor Coulomb interaction introduces charge disproportionation, which has the same spatial periodicity as the Wigner crystal, accompanied by a modified antiferromagnetic phase. This is in accordance with the results of experiments on (TMTTF)$_2$Br and (TMTTF)$_2$SCN. Moreover, the antiferromagnetic phase of (DI-DCNQI)$_2$Ag is predicted to have a similar antiferromagnetic spin structure.

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Hitoshi Seo, Hidetoshi Fukuyama. 1997-04-04. Antiferromagnetic Phases of One-Dimensional Quarter-Filled Organic Conductors. https://doi.org/10.1143/jpsj.66.1249

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