Tests of anisotropic superconductivity using Josephson interferometers

使用约瑟夫森干涉仪测试各向异性超导

• 批准号: 16540327
• 负责人: SUMIYAMA Akihiko
• 金额: $ 1.79万
• 依托单位: University of Hyogo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540327/
• 关键词: heavy-fermion superconductor; Josephson effect; anisotropic superconductivity; d-wave superconductivity

The anisotropic order parameters of heavy-fermion superconductors have been investigated for UPt_3, CeIrIn_5 and CePt_3Si using Josephson junctions, especially Josephson interferometers that can detect the phase difference of the order parameter between two directions.The corner junction on the UPt_3 faces perpendicular to the a[112^^-0] and b[101^^-0] axes has not shown a behavior indicating the phase shift of the order parameter between the a- and b-axis directions thus far. Even if the geometric asymmetry of the corner junction is taken into account, this result contradicts, for example, the two-dimensional E_<2u> scenario for the order parameter in UPt_3.The magnetic-field modulation of the Josephson critical current between a single-crystal CeIrIn_5 and an s-wave superconductor has shown a nearly ideal Fraunhofer pattern in the [100] direction and a small deviation from that pattern in the [110] direction. The indication of the d-wave superconductivity has not been observed clearly for the corner junction on the (100) and (010) faces, probably because of the asymmetry of the junction.In the magnetic-field dependence of I_c between a single crystal CePt_3Si and Al, a dominant maximum peak at zero field has been observed only for the junction on the a-axis face thus far, indicating that the Josephson effect is allowed at least for current flow parallel to the a axis. The randomly oscillating pattern for the junction on the c-axis face may be ascribed to the magnetic-flux trapping or the broken time-reversal symmetry in noncentrosymmetric superconductors.

用约瑟夫森结研究了UPt_3，CeIrIn_5和CePt_3Si重费米子超导体的各向异性序参量，尤其是约瑟夫森干涉仪，它可以检测两个方向之间序参量的相位差，UPt_3上的角结垂直于a[112^^-0]和B[101^^-0]到目前为止，轴没有示出指示a轴和b轴方向之间的序参量的相移的行为。即使考虑角结的几何不对称性，这一结果也与<2u>UPt_3中序参量的二维E_情况相矛盾。CeIrIn_5单晶与s波超导体之间约瑟夫森临界电流的磁场调制在[100]方向上显示出接近理想的夫琅和费图案，在[110]方向上与该图案有很小的偏差。在（100）面和（010）面的角结中，d波超导性的指示还没有被清楚地观察到，可能是由于角结的不对称性.在单晶CePt_3Si和Al之间的I_c随磁场的变化关系中，迄今为止只在a轴面的角结中观察到零场处的最大主峰，这表明至少对于平行于A轴的电流流动允许约瑟夫森效应。在非中心对称超导体中，c轴面上的结的随机振荡图案可以归因于磁通俘获或时间反演对称性破缺。

项目成果

Tunneling effect for heavy-fermion superconductors

重费米子超导体的隧道效应

• 发表时间: 2005
• 期刊: Solid State Physics. (in Japanese) Vol.40
• 作者: H.Hiraka;et al.;Y.Muro;Akihiko Sumiyama
• 通讯作者: Akihiko Sumiyama

Josephson effect between CePt3Si and an s-wave superconductor

CePt3Si 与 s 波超导体之间的约瑟夫森效应

• DOI: 10.1143/jpsj.74.3041
• 发表时间: 2005
• 期刊: Journal of the Physical Society of Japan
• 影响因子: 1.7
• 作者: A. Sumiyama;Keisuke Nakatsuji;Y. Tsuji;Y. Oda;T. Yasuda;R. Settai;Y. Ōnuki
• 通讯作者: Y. Ōnuki

Phase-Sensitive Test of UPt3Using Josephson Interferometry

使用约瑟夫森干涉仪对 UPt3 进行相敏测试

• DOI: 10.1143/jpsjs.75s.110
• 发表时间: 2006
• 作者: A. Sumiyama;R. Hata;Y. Oda;N. Kimura;E. Yamamoto;Y. Haga;Y. Ōnuki
• 通讯作者: Y. Ōnuki

Magnetic-field modulation of the Josephson effect between UPt_3 and a conventional superconductor

UPt_3 和传统超导体之间约瑟夫森效应的磁场调制

• 发表时间: 2005
• 期刊: Physical Review B Vol.72
• 作者: T.Fujiwara;Y.Uwatoko;H.Fujii;K.Koyama;M.Motokawa;T.Shigeoka;Yutaka Kishimoto;T.Shigeoka;Y.Kishimoto;Y.Kishimoto;Y.Kishimoto;T.Shigeoka;Y.Muro;H.Chudo;H.Nakamura;Akihiko Sumiyama;Akihiko Sumiyama;Akihiko Sumiyama
• 通讯作者: Akihiko Sumiyama

重い電子系超伝導のトンネル効果

重电子超导中的隧道效应

• 发表时间: 2005
• 期刊: 固体物理 40
• 作者: M.Fujita;et al.;H.Sato;R.Ikeno;住山 昭彦
• 通讯作者: 住山 昭彦