2015 Fiscal Year Final Research Report
Novel quantum states induced by valence and orbital fluctuations
| Project/Area Number |
25707030
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| Research Category |
Grant-in-Aid for Young Scientists (A)
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| Allocation Type | Partial Multi-year Fund |
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| Research Field |
Condensed matter physics II
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 価数揺らぎ / 軌道揺らぎ / 量子臨界現象 / スピン・軌道液体 / 重い電子超伝導 / 異常金属 |
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| Outline of Final Research Achievements |
Our study revealed the following novel quantum states in correlated electron systems. (1) In the valence fluctuating system β-YbAlB4, we found that a quantum criticality is stable in the finite range of pressure and appears without magnetic criticality, suggesting a formation of a strange metal phase due to strong valence fluctuations. Secondly, our success in growing a high quality single crystal of the quadrupolar heavy fermion system PrV2Al20 lead us to discover that PrV2Al20 exhibits a heavy fermion superconductivity in the anti-quadrupolar ordered phase. Furthermore, our pressure measurements found that this superconductivity is most likely driven by the quantum critical quadrupolar fluctuations. (2) In our studies on Ba3CuSb2O9, we reported the first observation of striking absence of the static Jahn-Teller distortion down to the lowest temperature, and the first determination of dynamic Jahn-Teller frequencies, indicating the formation of a quantum spin-orbital liquid state.
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| Free Research Field |
固体物理（実験）
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