在高化学和结构质量的TlPDMATHABMM Ba $_2$ Ca $_2$ Cu $_3$ O $_{10}$单晶中测量了Meissner转变周围的面内抗磁性,这最小化了对磁化的不均匀性和无序圆化效应。当定量分析和一致的Ginzburg-Landau(GL)的方法与库珀对和涡旋的波动的过渡上下时,这些数据提供了进一步的确认,所观察到的迈斯纳转变是一个传统的GL超导转变在一个均匀的层状超导体。
英文摘要:
The in-plane diamagnetism around the Meissner transition was measured in a Tl$_2$Ba$_2$Ca$_2$Cu$_3$O$_{10}$ single crystal of high chemical and structural quality, which minimizes the inhomogeneity and disorder rounding effects on the magnetization. When analyzed quantitatively and consistently above and below the transition in terms of the Ginzburg-Landau (GL) approach with fluctuations of Cooper pairs and vortices, these data provide a further confirmation that the observed Meissner transition is a conventional GL superconducting transition in a homogeneous layered superconductor.
Diamagnetism of real-space pairs above Tc in hole doped cuprates
Lu Li等人[Phys.Rev.B81,054510(2010)]报道的非线性正常态抗磁性显示出与在电阻性临界温度以上的广受好评的库珀配对和涡旋液体不相容。相反,它与实空间组成玻色子的正常态朗道抗磁性完全兼容,朗道抗磁性描述了在整个可用磁场范围内,各向异性较小的铜酸盐La-Sr-Cu-O(LSCO)和Y-Ba-Cu-O(YBCO)以及强各向异性铋基铜酸盐的非线性磁化曲线。
The diamagnetism above the superconducting transition in underdoped La(1.9)Sr(0.1)CuO(4) revisited: Chemical disorder or phase incoherent superconductivity?
超导波动和不均匀性之间的相互作用提出了一个新的兴趣,由于最近的工作支持一个异常的[超越传统的高斯-金兹伯格-朗道(GGL)的情况下]抗磁性高于Tc在欠掺杂的铜酸盐。这一结论主要是基于低场等温磁化曲线中新异常的观察,与我们早期在欠掺杂La(1.9)Sr(0.1)CuO(4)[Phys. Rev. Lett. 84,3157(2000)]。这些看似内在的反常现象在各种有影响力的著作中被作为赝能隙区相位非相干超导性的“热力学证据”提出,这是目前铜酸盐超导体物理学的一个中心和有争议的问题。在这里,我们已经扩展了我们的磁化强度测量在La(1.9)Sr(0.1)CuO(4)的两个样品具有不同的化学无序,在其中一个接近与随机分布的Sr离子。对于该样品,相应的Tc分布可以近似为围绕平均Tc对称,而在最无序的样品中是强烈不对称的。在这两个样品中测量的磁化强度之间的比较提供了一个关键的检查所观察到的抗磁性异常,这是类似于那些声称由于相位波动由其他作者的化学无序起源。这一结论也适用于只受本征类化学无序影响的样品,提供了进一步的检查,即在正常状态下的赝能隙的打开不影响低掺杂铜酸盐的超导转变以上的本征抗磁性。它还表明,一旦这些障碍的影响被克服,剩余的前体抗磁性可以占在一个定量水平的GGL方法下的总能量截止。
It is often claimed that among the strongest evidence for preformed-pair physics in the cuprates are the experimentally observed large values for the diamagnetic susceptibility and Nernst coefficient. These findings are most apparent in the underdoped regime, where a pseudogap is also evident. While the conventional (Gaussian) fluctuation picture has been applied to address these results, this preformed-pair approach omits the crucial effects of a pseudogap. In this paper we remedy this omission by computing the diamagnetic susceptibility and Nernst coefficient in the presence of a normal stat…
Diamagnetic susceptibility obtained from the six-vertex model and its implications for the high-temperature diamagnetic state of cuprate superconductors
The hallmark of superconductivity is the rigidity of the quantum-mechanical phase of electrons, responsible for superfluid behavior and Meissner effect. The strength of the phase stiffness is set by the Josephson coupling, which is strongly anisotropic in layered superconducting cuprates. So far, THz light pulses have been efficiently used to achieve non-linear control of the out-of-plane Josephson plasma mode, whose frequency scale lies in the THz range. However, the high-energy in-plane plasma mode has been assumed to be insensitive to THz pumping. Here, we show that THz driving of both low-…
The interpretation of how superconductivity disappears in cuprates at large hole doping has been controversial. To address this issue, we present an experimental study of single-crystal and thin film samples of La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) with $x\ge0.25$. In particular, measurements of bulk susceptibility on LSCO crystals with $x=0.25$ indicate an onset of diamagnetism at $T_{c1}=38.5$ K, with a sharp transition to a phase with full bulk shielding at $T_{c2}=18$ K, independent of field direction. Strikingly, the in-plane resistivity only goes to zero at $T_{c2}$. Inelastic neutron scatterin…
Probing the Meissner effect in single crystals of $\mathbf{Bi_2Sr_2Ca_2Cu_3O_{10+δ}}$ via wide-field quantum microscopy under high pressure
School of Engineering, Institute of Science Tokyo(东京科学大学工学院);Research Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science(物质材料研究机构纳米结构研究中心);Department of Mechanical and Electrical Systems Engineering, Kyoto University of Advanced Science (KUAS)(京都先端科学大学机电系统工程学院);National Institutes for Quantum Science and Technology (QST)(量子科学技术研究开发机构)