本文报道了CePt_2In_7单晶的温度-压力（T-P）相图，特别是反铁磁序的压力演化和超导电性的出现，并在近流体静力学环境下用电阻率和交流量热法进行了研究。与多晶超导体相比，体超导与反铁磁共存的压力范围要窄得多。在CePt 2 In 7中也观察到了织构超导性和局域量子临界性的可能存在，表现出与CeRhIn 5的显著相似性。
英文摘要：
We report the temperature-pressure (T-P) phase diagram of CePt2In7 single crystals, especially the pressure evolution of the antiferromagnetic order and the emergence of superconductivity, which have been studied by electrical resistivity and ac calorimetry under nearly hydrostatic environments. Compared with its polycrystalline counterpart, bulk superconductivity coexists with antiferromagnetism in a much narrower pressure region. The possible existence of textured superconductivity and local quantum criticality also are observed in CePt2In7, exhibiting a remarkable similarity with CeRhIn5.
Gigantic anisotropic uniaxial pressure effect on superconductivity within the CuO2 plane of La1.64Eu0.2Sr0.16CuO4 - strain control of stripe criticality
Pressure-induced superconductivity beyond magnetic quantum criticality in a Kondo ferromagnet
New Cornerstone Science Laboratory, Center for Correlated Matter and School of Physics, Zhejiang University（浙江大学物理学院关联物质中心新基石科学实验室）；Hubei Key Laboratory of Photoelectric Materials and Devices, School of Materials Science and Engineering, Hubei Normal University（湖北师范大学材料科学与工程学院光电材料与器件湖北省重点实验室）
Electronic nematicity in correlated metals often occurs alongside another instability such as magnetism. As a result, the question remains whether nematicity alone can drive unconventional superconductivity or anomalous (quantum critical) transport in such systems. In FeSe, nematicity emerges in isolation, providing a unique opportunity to address this question. Studies to date, however, have proved inconclusive; while signatures of nematic criticality are observed upon sulfur substitution, they appear to be quenched under the application of pressure due to the emergent magnetism. Here, we stu…
Wide Quantum Critical Region of Valence Fluctuations: Origin of Robust Quantum Criticality in Quasicrystal Yb15Al34Au51 under Pressure
从理论上分析了重电子准晶Yb_（15）Al_（34）Au_（51）中强量子临界的产生机制。通过对含有Yb和Al-Au团簇的同心壳结构准晶及其近似晶体建立极小模型，我们发现Yb的一级价跃迁的量子临界点在基态相图中以点的形式出现.它们的临界区相互重叠，从而产生宽的量子临界区。这很好地解释了在Yb 15 Al 34 Au51中观察到的压力下的鲁棒临界性，并预测了在压力下的晶体近似物中的共同临界性的出现。在T-P相图中，准晶中的临界区比晶态近似体中的临界区宽，在T-H相图中，准晶中的临界区将出现场诱导的价键交叉“区”。
在Yb基周期晶体如YbRh $_2$ Si $_2$和$β$ -YbAlB $_4$中观察到的非常规量子临界现象一直是强关联电子系统的中心问题之一。在准晶体Yb $_{15}$ Au $_{51}$ Al $_{34}$中发现了共同的临界性，其在至少高达$P=1.5$ GPa的压力下令人惊讶地持续存在。在准晶体中发现了$T/H$标度，其中磁化率可以表示为温度$T$与磁场$H$之比的单一标度函数，这与在$β$ -YbAlB $_4$中观察到的标度基本相同.最近，在压力下，甚至在近似晶体Yb $_{14}$ Au $_{51}$ Al $_{35}$中也观察到了$T/H$标度以及共临界性。Yb的临界价涨落理论对这些引人注目的现象给出了统一的自然解释。
Signatures of quantum criticality in hole-doped and chemically pressurized EuFe_2As_2 single crystals
通过测量热电势$S(T)$和电阻率$ρ(T)$，研究了$_x$ Eu $_{1-x}$ Fe $_2$ As $_2$和EuFe $_2$（As $_{1-y}$ P $_y$）$_2$单晶中空穴掺杂和化学压力（等价掺杂）的效应.掺杂后$S(T)$的演变表明，在临界值$x_{\mathrm{cr}}=0.3$和$y_{\mathrm{cr}}=0.21$，分别电子配置的急剧变化，自旋密度波跃迁被完全抑制和超导性（SC）出现。对于化学压力的情况下，与已发表的ARPES测量结果的比较表明，在$y_{cr}$的Lifshitz转变。温度依赖性$S(T)/T\propto \log T$和$Δρ\propto T$观察到的正常状态以上的SC过渡建议在这两个系统中的量子临界。
We show that including pairing and repulsion into the description of 1D spinless fermions, as in the domain wall theory of commensurate melting or the interacting Kitaev chain, leads, for strong enough repulsion, to a line of critical points in the eight vertex universality class terminating floating phases with emergent U(1) symmetry. For nearest-neighbor repulsion and pairing, the variation of the critical exponents along the line that can be extracted from Baxter's exact solution of the XYZ chain at $J_x=-J_z$ is fully confirmed by extensive DMRG simulations of the entire phase diagram, and…
Non-Divergent Grüneisen Parameter in Quantum Critical Quasicrystal Yb$_{15}$Al$_{34}$Au$_{51}$: Reflection of Robustness of Quantum Criticality under Pressure
分析了量子临界重费米子准晶Yb $_{15}$ Al $_{34}$ Au $_{51}$中Grüneisen参数不发散的机制。我们建立了计算Yb价态跃迁量子临界点附近的比热$C_V(T)$、热膨胀系数$α(T)$和Grüneisen参数$Γ(T)$的形式。通过将框架应用于QC，我们计算了$C_V(T)$、$α(T)$和$Γ(T)$，这解释了测量。不发散$Γ(T)$归因于压力下QC中量子临界性的稳健性。在$Γ(T)$在QC和近似晶体之间的最低温度的差异示出，以反映在临界Yb-价涨落和近藤温度的特征能量尺度的体积导数的差异。我们的理论对未来实验的可能影响也进行了讨论。
LaCrGe$_3$ has attracted attention as a paradigm example of the avoidance of ferromagnetic (FM) quantum criticality in an itinerant magnet. By combining thermodynamic, transport, x-ray and neutron scattering as well as $μ$SR measurements, we refined the temperature-pressure phase diagram of LaCrGe$_3$. We provide thermodynamic evidence (i) for the first-order character of the FM transition when it is suppressed to low temperatures and (ii) for the formation of new phases at high pressures. From our microscopic data, we infer that short-range FM ordered clusters exist in these high-pressure pha…
Quenched nematic criticality separating two superconducting domes in an iron-based superconductor under pressure
电子态及其相关的临界涨落已经成为各种非常规超导体中超导配对的潜在候选者。然而，在大多数材料中，它们与其他磁有序相的共存对确定它们的重要性提出了重大挑战。在这里，通过结合化学和流体静力学的物理压力在FeSe $_{0.89}$ S $_{0.11}$，我们提供了一个独特的访问一个干净的量子相变的情况下的远程磁秩序。我们发现在超导相变附近，高温下电阻率的非费米液体行为在最低温度下演变为费米液体行为。从高磁场中的量子振荡，我们跟踪费米面和电子关联的演化作为施加压力的函数。我们检测实验的Lifshitz过渡，分离两个不同的超导区域：一个新兴的电子相位与一个小的费米面和强电子相关性和其他一个大的费米面和弱相关性，促进嵌套和稳定的磁有序相在高压下。质量发散的缺乏表明临界涨落被晶格的强耦合淬灭。这表明在没有磁序的情况下，超导性在量子相变时不会增强。
Phase diagram and quantum criticality of Heisenberg spin chains with Ising-like interchain couplings -- Implication to YbAlO$_3$
受准一维量子反铁磁体场致相变研究进展的启发，我们利用大规模量子蒙特卡罗模拟方法研究了纵向磁场作用下具有Ising各向异性链间耦合的$S=1/2$反铁磁海森堡链的相图.链间的相互作用，以增强纵向自旋相关稳定在低温下的无公度纵向自旋密度波秩序。随着磁场的增加，基态变为倾斜的反铁磁序，直到磁化强度完全饱和到由$(3+2)$ D XY普适性控制的量子临界点以上。在量子临界状态下，随着温度的升高，系统经历了一个迷人的维度交叉，成为一种通用的Tomonaga-Luttinger液体。计算的NMR弛豫速率$1/T_1$表明这种Luttinger液体行为在宽场和温度范围内存活。我们的结果确定了准一维自旋链化合物一般模型的全局相图和量子临界性的定量特征，从而为这类材料的研究奠定了坚实的基础。
Neutron Scattering Study of URu$_{2-x}$Re$_x$Si$_2$ with $x$ = 0.10: Driving Order towards Quantum Criticality
我们报道了URu $_{2-x}$ Re $_x$ Si $_2$（其中$x$ = 0.10）的隐序态的非弹性中子散射测量。我们观察到，朝向由Re掺杂的负化学压力引起的铁磁量子临界点，带隙的无公度波动是鲁棒的，并且在强度上与母体材料相当。当Re掺杂使系统向量子临界点移动时，与隐藏顺序相关的相称的自旋波动减弱，显示缩短的寿命并减慢。在量子临界点的中途，隐藏的有序相幸存下来，尽管被削弱了，与其被静水压力和Rh掺杂的正化学压力破坏相反。
We present a comprehensive dynamical mean field study of the triangular lattice moiré Hubbard model, which is believed to represent the physics of moiré bilayer transition metal dichalcogenides. In these materials, important aspects of the band structure including the bandwidth and the order and location of van Hove singularities can be tuned by varying the interlayer potential. We present a magnetic and metal-insulator phase diagram and a detailed study of the dependence of the resistivity on temperature, band filling and interlayer potential. We find that transport displays Fermi liquid, str…
