Superconducting gap anisotropy sensitive to nematic domains in FeSe
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- 笠原, 成
- Institute for Solid State Physics (ISSP), University of Tokyo
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- Ota, Yuichi
- Institute for Solid State Physics (ISSP), University of Tokyo
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- Yamamoto, Haruyoshi Q.
- Institute for Solid State Physics (ISSP), University of Tokyo
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- Suzuki, Yuya
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, University of Tokyo
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- Shimojima, Takahiro
- Quantum-Phase Electronics Center (QPEC) and Department of Applied Physics, University of Tokyo
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- Watanabe, Shuntaro
- Research Institute for Science and Technology, Tokyo University of Science
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- Chen, Chuangtian
- Beijing Center for Crystal R&D, Chinese Academy of Science (CAS)
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- Kasahara, Shigeru
- Department of Physics, Kyoto University
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- Matsuda, Yuji
- Department of Physics, Kyoto University
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- Shibauchi, Takasada
- Department of Advanced Materials Science, University of Tokyo
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- Okazaki, Kozo
- Institute for Solid State Physics (ISSP), University of Tokyo
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- Shin, Shik
- Institute for Solid State Physics (ISSP), University of Tokyo
抄録
The structure of the superconducting gap in unconventional superconductors holds a key to understand the momentum-dependent pairing interactions. In superconducting FeSe, there have been controversial results reporting nodal and nodeless gap structures, raising a fundamental issue of pairing mechanisms of iron-based superconductivity. Here, by utilizing polarization-dependent laser-excited angle-resolved photoemission spectroscopy, we report a detailed momentum dependence of the gap in single- and multi-domain regions of orthorhombic FeSe crystals. We confirm that the superconducting gap has a twofold in-plane anisotropy, associated with the nematicity due to orbital ordering. In twinned regions, we clearly find finite gap minima near the vertices of the major axis of the elliptical zone-centered Fermi surface, indicating a nodeless state. In contrast, the single-domain gap drops steeply to zero in a narrow angle range, evidencing for nascent nodes. Such unusual node lifting in multi-domain regions can be explained by the nematicity-induced time-reversal symmetry breaking near the twin boundaries.
収録刊行物
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- Nature Communications
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Nature Communications 9 282-, 2018-01-18
Springer Nature
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詳細情報
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- CRID
- 1050001338207720192
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- NII論文ID
- 120006529718
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- ISSN
- 20411723
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- HANDLE
- 2433/234675
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- 本文言語コード
- en
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- 資料種別
- journal article
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- データソース種別
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