Shear Modulus Anomaly of Unconventional Superconductor in a Symmetry Breaking Field

非局部London模型中涡格的弹性模量

Elastic moduli of vortex lattices within nonlocal London model

采用非局部London模型分析涡格弹性响应。在VL经历正方形到菱形结构转变的场$H_{\Box}$处，挤压模量变为零。在正方形VL稳定的场区域$H>H_{\Box}$中，旋转模量在表示正方形VL相对于旋转的不稳定性的场$H_r$处变为零。剪切模量取决于剪切方向;在$H_{\Box}$附近的依赖性很强，在这里正方形VL相对于沿[110]的剪切是软的。计算了LuNi $_2$ B $_2$ C的弹性模量与$H$的关系。

非孪晶$\rm YBa_2Cu_3O_7$熔化转变时涡格电感和剪切模量的坍缩

Collapse of the vortex-lattice inductance and shear modulus at the melting transition in untwinned $\rm YBa_2Cu_3O_7$

在2 T磁场$\bf H\parallel c$中，在100 kHz至20 MHz的频率下，使用4探针RF传输技术测量了93 K $\rm YBa_2Cu_3O_7$的非孪晶晶体中涡旋晶格的复电阻率$\hatρ(ω)$，该技术能够连续测量相对于$ω$和温度$T$的$ω/2π$。随着$T$的增加，电感${\cal L}_s(ω) ={\rm Im} \hatρ(ω)/ ω$急剧增加到熔融温度$T_m$处的尖点，然后经历与剪切模量$c_{66}$的消失一致的急剧塌陷。我们详细讨论了分离的涡格电感的“体积”电感，和其他集肤深度的影响。为了分析光谱，我们考虑具有低钉密度的弱无序晶格。在$ω$中，在20年内获得了与$ρ_1(ω)$的密切拟合。得到的钉扎参数$κ$和剪切模量$c_{66}$的值表明，$c_{66}$在$T_m$处塌陷超过40年，而$κ$保持有限。

Linear Response Theory for Shear Modulus $C_{66}$ and Raman Quadrupole Susceptibility: Significant Evidence for Orbital Nematic Fluctuations in Fe-Based Superconductors

The emergence of the nematic order and fluctuations has been discussed as a central issue in Fe-based superconductors. To clarify the origin of the nematicity, we focus on the shear modulus $C_{66}$ and the Raman quadrupole susceptibility $χ_{x^2-y^2}^{Raman}$. Due to the Aslamazov-Larkin vertex correction, the nematic-type orbital fluctuations are induced, and they enhances both $1/C_{66}$ and $χ_{x^2-y^2}^{Raman}$ strongly. However, $χ_{x^2-y^2}^{Raman}$ remains finite even at the structure transition temperature $T_S$, because of the absence of the band Jahn-Teller effect and the Pauli (=in…

Origin of Orthorhombic Transition, Magnetic Transition, and Shear Modulus Softening in Iron Pnictide Superconductors: Analysis based on the Orbital Fluctuation Theory

The main features in iron-pnictide superconductors are summarized as (i) the orthorhombic transition accompanied by remarkable softening of shear modulus, (ii) high-Tc superconductivity close to the orthorhombic phase, and (iii) stripe-type magnetic order induced by orthorhombicity. To present a unified explanation for them, we analyze the multiorbital Hubbard-Holstein model with Fe-ion optical phonons based on the orbital fluctuation theory. In the random-phase-approximation (RPA), a small electron-phonon coupling constant ($λ~ 0.2$) is enough to produce large orbital (=charge quadrupole) flu…

有限厚度超导薄膜涡旋晶格的弹性性质

Elastic Properties of the Vortex Lattice for a Superconducting Film of Finite Thickness

本文研究了有限厚度超导薄膜涡旋晶格的弹性性质。我们推导出压缩模量的解析表达式。剪切模量的数值计算使用珍珠相互作用潜力，有效的限制非常薄膜，和一个潜在的膜的任意厚度。剪切模量进行了比较研究。

Unconventional Vortex Dynamics in Mesoscopic Superconducting Corbino Disks

The discrete shell structure of vortex matter strongly influences the flux dynamics in mesoscopic superconducting Corbino disks. While the dynamical behavior is well understood in large and in very small disks, in the intermediate-size regime it occurs to be much more complex and unusual, due to (in)commensurability between the vortex shells. We demonstrate unconventional vortex dynamics (inversion of shell velocities with respect to the gradient driving force) and angular melting (propagating from the boundary where the shear stress is minimum, towards the center) in mesoscopic Corbino disks.

非常规超导体CeCoIn_5磁通线晶格的新高场态

New High Field State of Flux Line Lattice in Unconventional Superconductor CeCoIn_5

超声波速度测量的非常规超导体CeCoIn_5具有极大的泡利顺磁磁化率揭示了一个不寻常的结构转变的磁通线晶格（FLL）附近的上临界场。过渡场与热容测量揭示的二阶相变相一致。在过渡的声速的降低是一致的崩溃的FLL倾斜模量和交叉准二维FLL钉扎。这些结果提供了强有力的证据表明，高场状态是Fulde-Ferrel-Larkin-Ovchinikov相，其中的序参量是空间调制的，并具有垂直于涡旋排列的平面节点。

晶体色超导夸克物质的刚性

The rigidity of crystalline color superconducting quark matter

我们计算的晶体色超导夸克物质的剪切模量，表明这一阶段的密集，但不是渐近密集，三味夸克物质响应剪切应力像一个非常刚性的固体。为了评估的剪切模量，我们推导出的低能有效拉格朗日描述的声子，起源于自发打破的平移不变性的间隙参数$Δ$的空间调制。这些无质量玻色子描述了晶体结构的空间和时间依赖性波动，类似于普通晶体中的声子。声子有效拉格朗日量的空间导数项的系数与晶体的弹性模量有关;编码晶体对剪切应力的线性响应的系数定义了剪切模量。我们分析了两种特殊的晶体结构，这是积极的密度范围很广，在每种情况下，评估声子的有效作用和剪切模量的顺序$Δ^2$在金斯堡-朗道膨胀，发现剪切模量是20至1000倍以上的中子星地壳。晶体色超导相长期以来被认为是一种超流体--通过选择一个相，它的序参量自发地打破了夸克数$U(1)_B$对称性。我们的研究结果表明，这种超流相的物质是在同一时间的刚性固体。最后，我们粗略估计了旋转涡旋上的钉扎力，这些旋转涡旋将在旋转时嵌入在这种刚性超流体中形成。我们的研究结果提出了一种可能性，即（某些）脉冲星故障可能起源于中子星深处的夸克物质核心。