ORDER-PARAMETER SYMMETRY OF HIGH-T_cSUPERCONDUCTORS BY MEANS OF BULK PHYSICAL QUANTITY

高温超导体的大体积物理量的有序参数对称性

• 批准号: 08454100
• 负责人: ISHIDA Takekazu
• 金额: $ 4.99万
• 依托单位: Osaka Prefecture University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454100/
• 关键词: torque magnetometer; high-T_C superconductivity; order-parameter symmetry; YBa_2Cu_3O_7

The order parameter symmetry of high-T_0 superconductors has been investigated by means of the bulk physical quantity. This is in contrast with that many experiments were carried out on the basis of surface properties. We built a new torque magnetometer using a split-type 6-T superconducting magnet. The measurement program has been coded using HP-BASIC.The in-plane torque of an untwinned YBa_2Cu_3O_7 single crystal consists of two-fold and four-fold symmetries. The former comes from the mass anisotropy between m_a and m_b. The latter is related with the order parameter symmetry, and is consistent with the existing theories. Our results are not compatible with the d_<xy> symmetry but are in good accordance with the d_<x^2-y^2> symmetry. We consider that our findings are convincing because the magnetic torque reflects information over the whole crystal.

高T_0超导体的顺序参数对称性已经通过大量物理量进行了研究。这与许多实验是根据表面特性进行的。我们使用拆分型6-T超导磁铁构建了新的扭矩计。测量程序已使用HP-BASIC编码。未扭转的YBA_2CU_3O_7的平面内扭矩由两倍和四倍的对称性组成。前者来自M_A和M_B之间的质量各向异性。后者与顺序参数对称性有关，并且与现有理论一致。我们的结果与D_ <xy>对称性不兼容，但与D_ <X^2-Y^2>对称性相符。我们认为我们的发现令人信服，因为磁性扭矩反映了整个晶体上的信息。

项目成果

T.Mikayama, T.Ishida et al.: "Kim Critical State in Twinned YBa_2Cu_3O_7 Single Crystal." Advanced in Superconductivity. Vol.VIII (Springer-Verlag). 571-574 (1996)

T.Mikayama、T.Ishida 等人：“孪晶 YBa_2Cu_3O_7 单晶中的 Kim 临界态”。

T.Ishida et al.: "Vortex lattice melting in untwinned single crystal YBa_2Cu_3O_7 when field are applied parallel to CuO_2 plane." Advances in Superconductivity. X (in press). (1998)

T.Ishida 等人：“当场平行于 CuO_2 平面施加时，非孪晶单晶 YBa_2Cu_3O_7 中的涡旋晶格熔化。”

T.ISHIDA et al.: "Vortex Lattice Melting in Untuinred ・・・" Advauces in Supercon duetinty. Vol.X. 457-460 (1998)

T.ISHIDA 等人：“Untuinred 中的涡旋晶格熔化...”Advauces in Supercon duetinty（第 X 卷）。

T.Ishida et al.: "Role of Intrinsic Pinning for Melting Transition of YBa_2Cu_3O_<6.93> in the Parallel Field to CuO_2 Layers." Advances in Superconductivity. Vol.XI (Springer-Verlag, 1999), (accepted for publication).

T.Ishida 等人：“平行场中 YBa_2Cu_3O_<6.93> 熔化转变的内在钉扎作用到 CuO_2 层。”

T.Ishida et al.: "Vortex Pinning and Irreversibility Line in Single Crystal YBa_2Cu_3O_7 with Parallel Twin Boundaries." Advanced in Superconductivity. Vol.X (Springer-Verlag, 1998). 461-464

T.Ishida 等人：“具有平行双晶界的单晶 YBa_2Cu_3O_7 中的涡旋钉扎和不可逆线。”