### 抄録

Effects of possible orbital order in magnetic properties of two-dimensional spin gap system for CaV_{4}O_{9} are investigated theoretically. After analyzing experimental data, we show that single orbital models assumed in the literature are insufficient to reproduce the data. To understand the origin of the discrepancy, we assume that in d^{1} state of V, d_{xy} and d_{yz} orbitals have substantial contributions in the lowest-energy atomic level which leads to a double-degeneracy. We study possible configurations of the orbital order. By exact diagonalization and perturbation expansion, we calculate the susceptibility, wavenumber dependence of low-lying excitations and equal-time spin-spin correlations which is related to integrated intensity of the neutron inelastic scattering. These quantities sensitively depend on the configuration of the orbital order. The calculated results for some configurations of the orbital order reproduce many experimental results much better than the previous single-orbital models. However some discrepancy still remains to completely reproduce all of the reported experimental results. To understand the origin of these discrepancies, we point out the possible importance of the partially occupied d_{xy} orbital in addition to orbital order of partially filled d_{xy} and d_{yz} orbitals.

元の言語 | English |
---|---|

ページ（範囲） | 564-575 |

ページ数 | 12 |

ジャーナル | Journal of the Physical Society of Japan |

巻 | 67 |

発行部数 | 2 |

DOI | |

出版物ステータス | Published - 1998 1 1 |

外部発表 | Yes |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)

### これを引用

**Orbital Order Effect of Two-Dimensional Spin Gap System for CaV _{4}O_{9} .** / Katoh, Nobuyuki; Imada, Masatoshi.

研究成果: Article

_{4}O

_{9}',

*Journal of the Physical Society of Japan*, 巻. 67, 番号 2, pp. 564-575. https://doi.org/10.1143/JPSJ.67.564

}

TY - JOUR

T1 - Orbital Order Effect of Two-Dimensional Spin Gap System for CaV4O9

AU - Katoh, Nobuyuki

AU - Imada, Masatoshi

PY - 1998/1/1

Y1 - 1998/1/1

N2 - Effects of possible orbital order in magnetic properties of two-dimensional spin gap system for CaV4O9 are investigated theoretically. After analyzing experimental data, we show that single orbital models assumed in the literature are insufficient to reproduce the data. To understand the origin of the discrepancy, we assume that in d1 state of V, dxy and dyz orbitals have substantial contributions in the lowest-energy atomic level which leads to a double-degeneracy. We study possible configurations of the orbital order. By exact diagonalization and perturbation expansion, we calculate the susceptibility, wavenumber dependence of low-lying excitations and equal-time spin-spin correlations which is related to integrated intensity of the neutron inelastic scattering. These quantities sensitively depend on the configuration of the orbital order. The calculated results for some configurations of the orbital order reproduce many experimental results much better than the previous single-orbital models. However some discrepancy still remains to completely reproduce all of the reported experimental results. To understand the origin of these discrepancies, we point out the possible importance of the partially occupied dxy orbital in addition to orbital order of partially filled dxy and dyz orbitals.

AB - Effects of possible orbital order in magnetic properties of two-dimensional spin gap system for CaV4O9 are investigated theoretically. After analyzing experimental data, we show that single orbital models assumed in the literature are insufficient to reproduce the data. To understand the origin of the discrepancy, we assume that in d1 state of V, dxy and dyz orbitals have substantial contributions in the lowest-energy atomic level which leads to a double-degeneracy. We study possible configurations of the orbital order. By exact diagonalization and perturbation expansion, we calculate the susceptibility, wavenumber dependence of low-lying excitations and equal-time spin-spin correlations which is related to integrated intensity of the neutron inelastic scattering. These quantities sensitively depend on the configuration of the orbital order. The calculated results for some configurations of the orbital order reproduce many experimental results much better than the previous single-orbital models. However some discrepancy still remains to completely reproduce all of the reported experimental results. To understand the origin of these discrepancies, we point out the possible importance of the partially occupied dxy orbital in addition to orbital order of partially filled dxy and dyz orbitals.

KW - CaVO

KW - Orbital order

KW - Spin gap

UR - http://www.scopus.com/inward/record.url?scp=0032391311&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032391311&partnerID=8YFLogxK

U2 - 10.1143/JPSJ.67.564

DO - 10.1143/JPSJ.67.564

M3 - Article

AN - SCOPUS:0032391311

VL - 67

SP - 564

EP - 575

JO - Journal of the Physical Society of Japan

JF - Journal of the Physical Society of Japan

SN - 0031-9015

IS - 2

ER -