| Project/Area Number |
18H01173
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
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| Research Institution | Nagoya University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
堀田 知佐 東京大学, 大学院総合文化研究科, 准教授 (50372909)
安井 幸夫 明治大学, 理工学部, 専任教授 (80345850)
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000)
Fiscal Year 2021: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2020: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2019: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2018: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
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| Keywords | スピン液体 / 相互作用の競合 / 二量体格子 / 不純物効果 |
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| Outline of Final Research Achievements |
The principal investigator discovered that Ba3ZnRu2O9 was a spin-liquid candidate. In the present project, we have investigated this spin-liquid-like state both experimentally and theoretically. Experimentally, we have found a tiny anomaly in the specific heat near 100 K accompanied by subtle magnetic reflections in the neutron diffraction. This indicates faint magnetic order below 100 K. We have further found through muSR that this order coexists with liquid-like fluctuating spins. In this respect, this magnetic ground state is quite unique. From a theoretical aspect, we have clarified that this unique magnetic state is theoretically plausible by studying a two-dimensional antiferromagnetic dimer triangular lattice. Moreover, we have discovered a new state of weak ferromagnetism in the Nb substituted samples.
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| Academic Significance and Societal Importance of the Research Achievements |
磁性体の研究は物性物理学の王道である。我が国においては本多光太郎先生以来の長い伝統を持ち、世界的にも優れた成果を発信している分野である。本研究はその伝統に連なるものであり、磁性の源となるスピンがペアで3次元格子を作ったとき、どのような磁性が生じるかを実験的・理論的に明らかにした。本研究を通じて我々が見出した状態は、液体のように揺らぐスピンと、きちんと向きが固まって固体のように振る舞うスピンが共存した状態である。これはこれまでに知られていない新しい磁気基底状態であり、磁気物理、統計物理、固体量子論の進展に貢献できる成果である。さらに、乱れを導入することで、弱い強磁性相が生じることも発見した。
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