2015 Fiscal Year Final Research Report
Elucidation of electric quadrupole effects in multiband superconductors by ultrasonic measurements
| Project/Area Number |
26800184
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Condensed matter physics II
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| Research Institution | Niigata University |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2016-03-31
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| Keywords | マルチバンド超伝導 / 鉄系超伝導体 / 電気四極子 / 超音波計測 / 弾性定数 / 超音波吸収係数 |
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| Outline of Final Research Achievements |
We have measured the ultrasonic attenuation coefficients of iron-based superconductors Ba(Fe1-xCox)2As2 and A-15 Superconductor V3Si with multiband structure. Ultrasonic attenuation coefficients show divergent increase with divergent softening of elastic constants toward the structural phase transition. Because this behavior indicates a critical slowing down phenomenon of quadrupole, the structural phase transition is a ferro quadrupole phase transition. On the other hand, Ultrasonic attenuation coefficient only shows divergent increase toward the superconducting transition. We performed analysis and calculation to focus the rotation induced by transverse ultrasound. We clarified that two conduction electrons form a hexadecapole to create a bound state and the critical slowing down occurs, which shows that the fluctuation of the hexadecapole increases divergently.
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| Free Research Field |
物性物理学
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