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.

已经研究了使用约瑟夫森连接仪，尤其是约瑟夫森的干涉仪，可以检测到可以检测两个方向之间的顺序差异。轴尚未显示出指示迄今为止A-和B轴方向之间顺序参数的相移。即使考虑了角接口的几何不对称性，例如，该结果与UPT_3中的顺序参数的二维E_ <2U>相矛盾。 [110]方向。 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平行于A轴的流动。 C轴面上的连接点的随机振荡模式可以归因于非中心对称超导体中的磁性频率捕获或破裂的时间反转对称性。

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

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

重い電子系超伝導体のトンネル効果

重电子超导体中的隧道效应

• 发表时间: 2005
• 期刊: 固体物理 40
• 作者: T.Shigeoka;K.Ohishi;M.Fukuhara;M.Hedo;Y.Uwatoko;H.Hiraka et al.;M.W.Haverkort;Y.Muro;Yutaka Kishimoto;Hisashi Uzu;住山 昭彦
• 通讯作者: 住山 昭彦

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