Josephson plasma emission in the high temperature superconductor superlattice

高温超导超晶格中的约瑟夫森等离子体发射

• 批准号: 09554016
• 负责人: MATSUDA Yuji
• 金额: $ 3.46万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09554016/
• 关键词: Superconductivity; Josephson effect; Vortex state; Plasma oscillation; Columnar defect; Vortex lattice melting; 高温超伝導体; BCS理論; 重イオン照射; ジョセフソンプラズマ; ジョセフソン渦; ロックイン転移

Josephson plasma resonance is a powerful means to probe the vortex state of layered superconductors, enabling us to determine the interlayer Josephson coupling quantitatively. In this research projest, we have measured how the Josephson coupling changes when the vortex lattice melts into the liquid in highly anisotropic Bi_2Sr_2CaCu_2O_<8+6>. We showed that the Josephson coupling strength changes dramatically when going accross the melting line. This result shows that the vortex lattice undergoes the transition from the three dimentional lattice to the decoupled pancake gas. We also studied the effect of the heavy-ion-irradiation. We showed that the introduction of the columnar defects changes the Josephson coupling dramatically. The coupling transition in which the decoupled pancakes couple with magnetic field. This transition occurs almost one-third of the matching field. We calculated the correlation length of the pancekes along the c-axis quantitatively from the detailed analysis of the resonance.

约瑟夫森等离子体共振是探测层状超导体涡旋态的有力手段，使我们能够定量确定层间约瑟夫森耦合。在本研究项目中，我们测量了当涡晶格熔化到高度各向异性的 Bi_2Sr_2CaCu_2O_<8+6> 液体中时，约瑟夫森耦合如何变化。我们表明，当穿过熔线时，约瑟夫森耦合强度会发生巨大变化。该结果表明涡旋晶格经历了从三维晶格到解耦薄饼气体的转变。我们还研究了重离子照射的效果。我们表明，柱状缺陷的引入极大地改变了约瑟夫森耦合。耦合转变，其中解耦煎饼与磁场耦合。这种转变几乎发生在匹配场的三分之一处。通过对共振的详细分析，我们定量计算了 pancekes 沿 c 轴的相关长度。

项目成果

N.Chikumoto et al.: "Magnetic Study on the Field Driven Transition from..." Physical Review B. 57. 14507-14510 (1998)

N.Chikumoto 等人：“磁场驱动转变的磁学研究……”物理评论 B. 57. 14507-14510 (1998)

Y.Matsuda et al.: "Interlayer Phase Coherence in the Vortex State of Bi_2Sr_2CaCu_2O_ Probed by Josephson Plasma Resonance." Phys.Rev.Lett.78. 1972-1975 (1997)

Y.Matsuda 等人：“通过约瑟夫森等离子体共振探测 Bi_2Sr_2CaCu_2O_<8 delta> 涡旋态中的层间相位相干性。”

Y.Matsuda et al.: "Excitation of Josephson Plasma and Vortex Oscillation Modes in Bi_2Sr_2CaCu_2O_ in Parallel magnetic Fields." Phys.Rev.B55. R8685-8688 (1997)

Y.Matsuda 等人：“平行磁场中 Bi_2Sr_2CaCu_2O_<8 delta> 中约瑟夫森等离子体和涡旋振荡模式的激发”。

松田祐司: "固有ジョセフソン接合体としてみた高温超伝導体" 日本応用物理学会誌. 67. 435-439 (1998)

Yuji Matsuda：“高温超导体被视为本征约瑟夫森结”，日本应用物理学会杂志 67. 435-439 (1998)。

T.Nagaoka, Y.Matsuda et al.: "Hall Anomaly in the Superconducting State of High-T_c Superconductors ; Universality in Doping Dependence." Phys.Rev.Lett.80. 3594-3597 (1998)

T.Nagaoka、Y.Matsuda 等人：“高温超导体超导态的霍尔异常；掺杂依赖性的普遍性。”