2013 Fiscal Year Final Research Report
Exploring of quantum many-body effect in strongly frustrated spin systems
| Project/Area Number |
23244072
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
ONO Toshio 大阪府立大学, 理学系研究科, 准教授 (40332639)
KURITA Nobuyuki 東京工業大学, 大学院理工学研究科, 助教 (80566737)
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| Co-Investigator(Renkei-kenkyūsha) |
SATO Taku 東北大学, 多元物質科学研究所, 教授 (70354214)
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| Project Period (FY) |
2011-04-01 – 2014-03-31
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| Keywords | 磁性 / 量子スピン系 / フラストレーション / 強磁場 / 量子多体効果 / 三角格子反強磁性体 / 籠目格子反強磁性体 / スピンダイマー磁性体 |
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| Research Abstract |
We investigated remarkable quantum effects in strongly frustrated spin systems. We performed magnetization measurement on Ba3CoSb2O9, and provide evidence that a spin-1/2 Heisenberg antiferromagnet on a regular triangular lattice is actually realized in Ba3CoSb2O9. We found that the entire magnetization curve is in excellent quantitative agreement with the theoretical calculations.
Magnetic excitations in the spin-1/2 kagome lattice antiferromagnet Cs2Cu3SnF12 with an ordered ground state were studied using inelastic neutron scattering. Although the spin-wave dispersion can be qualitatively understood in terms of linear spin-wave theory (LSWT), the excitation energies are renormalized by a factor of approximately 0.6 from those calculated by LSWT. This result provides the first evidence of negative quantum renormalization. We determined the crystal structure of the spin dimer magnet Ba2CoSi2O6Cl2, and observed quantization of magnetization at half of the saturation magnetization.
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