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arXiv 2602.08358cond-mat.supr-con
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三重态对的自旋构型与UTe₂中超导性之间的亲密关系

Intimate relationship between spin configuration in the triplet pair and superconductivity in UTe$_2$

Kyoto University(京都大学);Japan Atomic Energy Agency(日本原子能机构);Tohoku University(东北大学)
Hiroki Matsumura, Yuki Takahashi, Riku Matsubayashi, Katsuki Kinjo, Shunsaku Kitagawa, Kenji Ishida, Yo Tokunaga, Hironori Sakai, Shinsaku Kambe, Motoi Kimata, … 展开作者

Hiroki Matsumura, Yuki Takahashi, Riku Matsubayashi, Katsuki Kinjo, Shunsaku Kitagawa, Kenji Ishida, Yo Tokunaga, Hironori Sakai, Shinsaku Kambe, Motoi Kimata, Ai Nakamura, Yusei Shimizu, Yoshiya Homma, Dexin Li, Fuminori Honda, Atsushi Miyake, Dai Aoki, Tetsuya Furukawa, Takahiro Sasaki

AI总结:

研究揭示UTe₂中三重态对自旋构型与超导上临界磁场H_c2的紧密关联,发现磁场方向影响H_c2大小,揭示三重态超导的独特特性。

摘要:

三重态超导性是一种引人入胜的量子相干态,具有自旋和轨道自由度,对未来的量子技术应用具有重要意义。然而,三重态对的自旋如何响应外部磁场仍不为人知。这主要是由于缺乏合适的三重态超导体。在此,我们报告了对UTe₂的Knight位移和交流磁化率测量结果。我们证明,自旋磁化率在超导(SC)转变温度T_c以下略低于正常态值,当施加磁场沿c轴(H∥c)时,该磁化率迅速恢复并接近正常态值,远低于超导上临界磁场H_c2。此外,我们发现当SC自旋与磁场对齐时,H_c2会增大。通过考虑H∥b的结果,我们的结果表明三重态对的自旋构型与H_c2之间存在密切关系,以及作用于三重态对的各向异性钉扎相互作用。这些现象,以前从未在自旋单态超导体中被观察到,代表了三重态超导体特有的特征。我们讨论了UTe₂中的超导性与超流^3He之间的相似性,重点在于它们的自旋三重态配对态。

英文摘要:

Spin-triplet superconductivity is an intriguing quantum coherent state with both spin and orbital degrees of freedom, which holds significant potential for future applications in quantum technology. However, how the spin of the triplet pairs responds to an external magnetic field remains poorly understood. This is mainly due to the absence of suitable spin-triplet superconductors. Here, we report results of Knight-shift and ac-susceptibility measurements on UTe$_2$. We demonstrate that the spin susceptibility, which slightly decreases compared to the normal-state value below the superconducting (SC) transition temperature $T_{\rm c}$, is rapidly restored and nearly recovers to the normal-state values around 5 T, well below the SC upper critical field $H_{c2}$ when the magnetic field is applied along the $c$ axis ($H \parallel c$). In addition, we found that $H_{\rm c2}$ of superconductivity becomes larger when the SC spin aligns with the magnetic field. By considering the results on $H \parallel b$, our results suggest the presence of a close relationship between the spin configuration of the triplet pair and $H_{\rm c2}$, as well as the anisotropic pinning interaction acting on the triplet pairs. These phenomena, which have never been observed in spin-singlet superconductors, represent characteristic features unique to spin-triplet superconductors. We discuss the similarities between superconductivity in UTe$_2$ and superfluid $^3$He, focusing on their spin-triplet pairing states.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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