2018 Fiscal Year Final Research Report
Study for electronic state of pressure-indeced superconductivity in iron-based ladder-type material and search for related superconductors
| Project/Area Number |
16H04019
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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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| Research Field |
Condensed matter physics II
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| Research Institution | Nihon University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
山内 徹 東京大学, 物性研究所, 技術専門職員 (10422445)
大串 研也 東北大学, 理学研究科, 教授 (30455331)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 梯子型鉄系化合物 / 圧力効果 / 超伝導 / 圧力誘起超伝導 |
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| Outline of Final Research Achievements |
We studied iron-based ladder-type materials showing pressure-induced superconductivity. The purpose is to elucidate the mechanism of such a novel superconductivity and to develop related superconductors. We found the pressure-induced metallization for the mixed crystal Ba1-xCsxFe2Se3. The end members BaFe2Se3 and CsFe2Se3 show block-type and stripe-type antiferromagnetism, respectively. Though superconductivity could not be found for Ba1-xCsxFe2Se3, resitance drop which may be related to superconductivity could be found for pristine single crystal of BaFe2Se3, which is successfully grown recently. For BaFe2Se3, metal-insulator transition was observed using both cubic anvil press and diamond anvil cell, but superconductivity was observed only in case for using diamond anvil cell. It is possible that the electronic properties under high pressure strongly depend on the quality of the pressure. We will study the relation between electrical properties and hydrostatic condition.
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| Free Research Field |
物性物理学
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| Academic Significance and Societal Importance of the Research Achievements |
これまでの鉄系超伝導体では、キャリアをドープする前の母相が半金属であるのに対し、はしご型鉄系超伝導体の母相はモット絶縁体である。また、鉄系超伝導体の超伝導対称性がs波的であったのに対し、はしご型鉄系超伝導体の超伝導対称性はd波的である事が理論的に予測されている。銅酸化物超伝導体が、モット絶縁体を母相とし、超伝導対称性がd波的であることを考えると、はしご型鉄系超伝導体の研究を進めることにより、鉄系超伝導体のみならず、銅酸化物も含めた、高温超伝導現象についての知見が得られる可能性があり、学術的に重要である。
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