2021 Fiscal Year Final Research Report
High-field ultrasonic study of quadrupole oprdering in electronic nematic state due to p-f hybridization
| Project/Area Number |
20K14404
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
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| Research Institution | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2020-04-01 – 2022-03-31
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| Keywords | 強相関電子系 / 電子ネマティック相 / 電気四極子 / 結晶対称性の破れ / 超音波計測 / 非破壊パルス強磁場 |
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| Outline of Final Research Achievements |
We investigated field-induced ordering and crystal symmetry breaking using ultrasonic measurements under pulsed-magnetic fields in CeTIn_5 and LaTIn_5 (T = Co, Rh, Ir). In the electronic nematic (EN) ordering in CeRhIn_5, the elastic constant with the irrep B_1g of the space group D_4h exhibits an anomaly. In contrast, we could not observe such an anomaly in LaRhIn_5. These results indicate that 4f electrons in Ce ions play a key role in the EN phase.
On the other hand, the elastic anomaly was not observed in LaIrIn_5 in addition to CeIrIn_5. Therefore, we concluded that the in-plane anisotropy of the p-f hybridization between Ce-4f and In-5p electrons contributed to the field-induced EN phase transition in CeRhIn_5.
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| Free Research Field |
強相関電子系の超音波計測
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| Academic Significance and Societal Importance of the Research Achievements |
本研究では，約30Tという強磁場中で顕著に異方化する電子状態の起源を解明するため，60 Tまでの磁場を容易に発生できる非破壊パルス強磁場と，異方的な電子状態の観測に長けた超音波計測を組み合わせた物性測定を推進した．その結果，化合物中のどの電子が異方的な電子状態の実現に寄与するかを解明した．
このような異方的な電子状態の起源は議論がつづいており，新たな学術的知見を獲得できた．
また本研究で得た知見によって，例えば磁場を用いて電流が流れる方向を操作するような新しいスイッチングデバイス実現など，将来的な産業への寄与も期待できる．
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