Charge order with structural distortion in organic conductors: Comparison between θ-(ET)2RbZn(SCN)4 and α-(ET) 2I3

Yasuhiro Tanaka, Kenji Yonemitsu

研究成果: Article

35 引用 (Scopus)

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Charge ordering with structural distortion in quasi-two-dimensional organic conductors θ-(ET)2RbZn(SCN)4 (ET = BEDT-TTF) and α-(ET)2I3 is investigated theoretically. By using the Hartree-Fock approximation for an extended Hubbard model which includes both on-site and intersite Coulomb interactions together with Peierls-type electron-lattice couplings, we examine the role of lattice degrees of freedom on charge order. It is found that the experimentally observed, horizontal charge order is stabilized by lattice distortion in both compounds. In particular, the lattice effect is crucial to the realization of the charge order in θ-(ET)2RbZn(SCN)4, while the peculiar band structure whose symmetry is lower than that of θ-(ET)2RbZn(SCN) 4 in the metallic phase is also an important factor in α-(ET)2I3 together with the lattice distortion. For α-(ET)2I3, we obtain a phase transition from a charge-disproportionated metallic phase to the horizontal charge order with lattice modulations, which is consistent with the latest X-ray experimental result.

元の言語English
記事番号034708
ジャーナルJournal of the Physical Society of Japan
77
発行部数3
DOI
出版物ステータスPublished - 2008 3 1
外部発表Yes

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conductors
Hartree approximation
degrees of freedom
modulation
symmetry
electrons
x rays
interactions

ASJC Scopus subject areas

  • Physics and Astronomy(all)

これを引用

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abstract = "Charge ordering with structural distortion in quasi-two-dimensional organic conductors θ-(ET)2RbZn(SCN)4 (ET = BEDT-TTF) and α-(ET)2I3 is investigated theoretically. By using the Hartree-Fock approximation for an extended Hubbard model which includes both on-site and intersite Coulomb interactions together with Peierls-type electron-lattice couplings, we examine the role of lattice degrees of freedom on charge order. It is found that the experimentally observed, horizontal charge order is stabilized by lattice distortion in both compounds. In particular, the lattice effect is crucial to the realization of the charge order in θ-(ET)2RbZn(SCN)4, while the peculiar band structure whose symmetry is lower than that of θ-(ET)2RbZn(SCN) 4 in the metallic phase is also an important factor in α-(ET)2I3 together with the lattice distortion. For α-(ET)2I3, we obtain a phase transition from a charge-disproportionated metallic phase to the horizontal charge order with lattice modulations, which is consistent with the latest X-ray experimental result.",
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AU - Yonemitsu, Kenji

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N2 - Charge ordering with structural distortion in quasi-two-dimensional organic conductors θ-(ET)2RbZn(SCN)4 (ET = BEDT-TTF) and α-(ET)2I3 is investigated theoretically. By using the Hartree-Fock approximation for an extended Hubbard model which includes both on-site and intersite Coulomb interactions together with Peierls-type electron-lattice couplings, we examine the role of lattice degrees of freedom on charge order. It is found that the experimentally observed, horizontal charge order is stabilized by lattice distortion in both compounds. In particular, the lattice effect is crucial to the realization of the charge order in θ-(ET)2RbZn(SCN)4, while the peculiar band structure whose symmetry is lower than that of θ-(ET)2RbZn(SCN) 4 in the metallic phase is also an important factor in α-(ET)2I3 together with the lattice distortion. For α-(ET)2I3, we obtain a phase transition from a charge-disproportionated metallic phase to the horizontal charge order with lattice modulations, which is consistent with the latest X-ray experimental result.

AB - Charge ordering with structural distortion in quasi-two-dimensional organic conductors θ-(ET)2RbZn(SCN)4 (ET = BEDT-TTF) and α-(ET)2I3 is investigated theoretically. By using the Hartree-Fock approximation for an extended Hubbard model which includes both on-site and intersite Coulomb interactions together with Peierls-type electron-lattice couplings, we examine the role of lattice degrees of freedom on charge order. It is found that the experimentally observed, horizontal charge order is stabilized by lattice distortion in both compounds. In particular, the lattice effect is crucial to the realization of the charge order in θ-(ET)2RbZn(SCN)4, while the peculiar band structure whose symmetry is lower than that of θ-(ET)2RbZn(SCN) 4 in the metallic phase is also an important factor in α-(ET)2I3 together with the lattice distortion. For α-(ET)2I3, we obtain a phase transition from a charge-disproportionated metallic phase to the horizontal charge order with lattice modulations, which is consistent with the latest X-ray experimental result.

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KW - Extended Hubbard model

KW - Hartree-Fock approximation

KW - Organic conductor

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