The verification of the universality of the stripe order in single crystal of cuprate superconductors

高Tc超导电性条纹模型是一个可行的，其中可以解释一个称为1/8的问题，命名为基于La-based Cupration的超导电性的异常抑制与每个铜孔集中的超导电性。它被提出了，即在中子散射实验中观察到的基于La-based的Cupration的静态顺序和旋转。如果条纹顺序是CuO_2平面的特征，它将不仅仅存在于基于La-based的Cupration中，但也存在其他高Tc Cupration。在本研究中，我们将按顺序搜索双基培养液中的1/8异常，我们调查了Bi_2Sr_2Ca_<1-x> Y_x（Cu_<1-y> Zn_y）_2O_<8+δ>单晶体。锌替代品被锌钉在条纹图案的静态顺序上。我们已经成功地成长了许多单一水晶与0 [小于或等于] x [小于或等于] 0.5， y = 0， 0.025通过浮动区方法，在顺序上被禁用以修复ex ... More cess oxygen content σ . The x dependence of Tc defined as the onset temperature of the Meissner effect has appeared a local minimum of Tc at x ~ 0.35 for y = 0， 0.025。目前，霍尔效应和热电功率已按顺序测量，以测试这个局部最小值和1/8问题的相关性。低尺寸量子自旋系统的热行为我们已经考虑到了大尺寸的热行为，如各种低尺寸量子自旋系统的磁轭，如两条腿自旋阶梯系统Sr_<14>Cu_<24>O_<41>，两个尺寸自旋二聚体系统SrCu_2（BO_3）_2，四条腿旋转阶梯系统La_2Cu_2O_5、两个尺寸旋转系统Cu_3B_2O_6和一个尺寸旋转系统Ca_2Y_2Cu_5O_<10>，使用TSFZ方法生长大尺寸的单晶体。在Sr_Cu_O_whose三条激发带宽度的自旋间隙状态中发现了较大的k magnon<14><24><41>，并导致了对magnons自由路径的增强。在无间隙的系统中，它发现了k磁轭增加的磁轭，其中铜^&lt;2+&gt;自旋中的反磁自旋相关系统比铁磁自旋相关系统中的磁轭增加的是k磁轭增加的，而铜^&lt;2+&gt;自旋之间的变大。因此，它被包括在一个自旋间隙系统中的三条激发的大带宽，一个较大的交换交互和反磁自旋相关比一个电磁自旋相关。Less（低）

・Stripe order of high-Tc superconductorThe stripe model is a plausible one which can explain the so-called 1/8 problem, namely, the anomalous suppression of superconductivity in the La-based cuprate with the hole concentration per Cu p 〜 1/8. It has been proposed that the static order of holes and spins observed in the La-based cuprate from the neutron scattering experiment. If the stripe order is characteristic of the CuO_2 plane, it will exist not only in the La-based cuprate but also other high-Tc cuprates with p 〜 1/8. In this study, in order to search for the 1/8 anomaly in the Bi-based cuprate, we investigated the superconducting transition temperature Tc of Bi_2Sr_2Ca_<1-x>Y_x(Cu_<1-y>Zn_y)_2O_<8+δ> single crystals. The Zn substitution is due to the stripe-patterned static order pinned by Zn. We have succeeded in growing of much kinds of single crystal with 0【less than or equal】x【less than or equal】0.5, y = 0, 0.025 by floating-zone method, which were annealed in order to fix ex … More cess oxygen content σ . The x dependence of Tc defined as the onset temperature of the Meissner effect has appeared a local minimum of Tc at x〜0.35 for y = 0, 0.025. At present, Hall effect and thermoelectric power are being measured in order to examine the correlation of this local minimum and 1/8 problem.Thermal conductivity of low-dimensional quantum spin systemWe have looked for large thermal-conductivity due to magnons, κmagnon in various kinds of low-dimensional quantum spin systems, such as the two-leg spin-ladder system Sr_<14>Cu_<24>O_<41>, the two-dimensional spin-dimer system SrCu_2(BO_3)_2, the four-leg spin-ladder system La_2Cu_2O_5, the two-dimensional spin system Cu_3B_2O_6 and the one-dimensional spin system Ca_2Y_2Cu_5O_<10>, using large-sized single-crystals grown by the TSFZ method. Large κmagnon has been found in the spin-gap state of Sr_<14>Cu_<24>O_<41> whose band width of the triplet excitation is large, owing to the enhancement of the mean free path of magnons. In gapless systems, it has been found that κmagnon increases with increasing magnon-velocity, which increases with increasing exchange-interaction between Cu^<2+> spins and is larger in antiferromagnetic spin-correlation systems than in ferrromagnetic spin-correlation systems. Therefore, it is concluded that essential factors of large κmagnon are a large band-width of the triplet excitation in a spin-gap system, a large exchange-interaction and antiferromagnetic spin-correlation rather than ferromagnetic spin-correlation. Less