Recent experimental findings show that the pairing interaction in hole-doped cuprates resides in the nodal (FS arcs) region accompanied by the separate antinodal pseudogap. A corresponding multiband model of cuprate superconductivity is developed. It is based on the electronic spectrum evolving with doping and extends authors earlier approaches. The leading pair-transfer interaction is supposed between the itinerant (mainly oxygen) band and a nodal defect (polaron) band created by doping. These components are overlapping. The defect subband created in the antinodal region of the momentum space does not participate in the pairing by symmetry arguments. A supposed bare gap separating it from the itinerant band top disappears with extended doping. The corresponding antinodal pseudogap appears as a perturbative band structure effect. The low energy excitation spectrum treated in the mean-field approximation includes two nodal superconducting gaps and one pseudogap. The behaviour of these gaps and of other pairing characteristics agree qualitatively with the observations on the whole doping scale.
Superconductivity distorted by the coexisting pseudogap in the antinodal region of Bi$_{1.5}$Pb$_{0.55}$Sr$_{1.6}$La$_{0.4}$CuO$_{6+δ}$: A photon-energy-dependent angle-resolved photoemission study
超导电性和赝能隙之间的相互作用是铜氧化物物理的一个重要方面。然而，赝能隙的性质仍然存在争议，部分原因是不同的实验提出了不同的能隙函数。本文采用光子能量依赖角分辨光电子能谱（ARPES）研究了Bi $_{1.5}$ Pb $_{0.55}$ Sr $_{1.6}$ La $_{0.4}$ CuO $_{6+δ}$ .我们发现，在低光子能量的反节ARPES谱是由背景信号，这可能会导致一个错误的评估的光谱间隙的大小占主导地位。一旦背景是适当的占，独立的光子能量，在不同的能量下，主要归因于赝能隙和超导性，以及偏离一个简单的d-波形式的整体光谱间隙的波腹光谱鲁棒地显示两个共存的功能。这些结果支持了赝能隙和超导性之间的竞争导致能隙畸变的观点。
Impurity-Scattering Assisted Umklapp Scattering as the Origin of Low-Temperature Resistivity in the Normal-State of Cuprate Superconductors
Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；College of Physics, Chongqing University（重庆大学物理学院）；School of Physics, Beihang University（北京航空航天大学物理学院）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；Department of Physics, Beijing Normal University, Zhuhai（北京师范大学珠海校区物理系）
Model for the occurrence of Fermi pockets without the pseudogap hypothesis in underdoped cuprate superconductors - Interplay of Jahn-Teller physics and Mott physics -
Two pseudogaps with different energy scales at the antinode of the high-temperature Bi$_2$Sr$_2$CuO$_6$ superconductor using angle-resolved photoemission spectroscopy
我们已经进行了高分辨率角分辨光电子能谱的单层铜酸盐Bi $_2$ Sr $_2$ CuO $_6$澄清的赝能隙的起源。通过使用不同的光子能量，我们已经成功地直接观察到两个不同的赝能隙与两个不同的能量尺度共存的波腹区域：一个反映了$d_{x^2-y^2}$波配对强度，而另一个具有较大的能量尺度，表明起源不同于超导。观察到的双赝能隙行为提供了一个关键，以充分理解赝能隙现象的铜酸盐。
Occurrence of Fermi Pockets without Pseudogap Hypothesis and Clarification of the Energy Distribution Curves of Angle-Resolved Photoemission Spectroscopy in Underdoped Cuprate Superconductors
Investigations on the relationship between $T_c$ and the superconducting gap under magnetic and non-magnetic impurity substitutions in YBa$_2$Cu$_3$O$_{7-δ}$
Quantitative Comparison between Electronic Raman Scattering and Angle-Resolved Photoemission Spectra in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ Superconductors: Doping Dependence of Nodal and Antinodal Superconducting Gaps
Probing the pseudogap and beyond: Examining single-particle properties of the hole- and electron-doped Hubbard model
Stanford University（斯坦福大学）；SLAC National Accelerator Laboratory（SLAC国家加速器实验室）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；University of Notre Dame（圣母大学）
Signatures of superconductivity and pseudogap formation in non-equilibrium nodal quasiparticles revealed by ultrafast angle-resolved photoemission
我们用时间分辨和角分辨光电子能谱测量了$_2$ $_2$ O $_2$的各种掺杂的节非平衡电子态。我们发现，这些ungapped状态的初始泵浦诱导的瞬态信号的强烈影响的超导能隙在$T_c$，超导配对波动在$T_p$，和赝能隙在$T^*$的发病。此外，$T_p$标记了通量依赖性瞬态信号中的一个提示性阈值，出现了低于$T_p$的临界通量，该临界通量对应于使所有库珀对断裂所需的能量。这些结果挑战了铜氧化物超导体中结-反结二分法的概念，在结准粒子和铜氧化物相图之间建立了一个新的联系。
Low-temperature T$^{2}$ resistivity in the underdoped pseudogap phase versus T-linear resistivity in the overdoped strange-metal phase of cuprate superconductors
Fermi surface and pseudogap in highly doped Sr$_{2}$IrO$_{4}$
University of Geneva（日内瓦大学）；Northeastern University（东北大学）；Quantum Materials and Sensing Institute, Northeastern University（东北大学量子材料与传感研究所）；Laboratory of Advanced Technology, University of Geneva（日内瓦大学先进技术实验室）；Universidad Complutense de Madrid（马德里康普顿斯大学）；Paul Scherrer Institut（保罗谢勒研究所）；Swiss Light Source, Paul Scherrer Institut（保罗谢勒研究所瑞士光源）；Zhejiang University（浙江大学）
Direct measurement of coherent nodal and antinodal dynamics in underdoped Bi-2212
Swinburne University of Technology（斯威本科技大学）；University of New South Wales（新南威尔士大学）；University of Brescia（布雷西亚大学）；Quantum Matter Institute, University of British Columbia（不列颠哥伦比亚大学量子物质研究所）；Institut National de la Recherche Scientifique（国家科学研究学院）；Materials Science Division of Brookhaven National Laboratory（布鲁克海文国家实验室材料科学部）；Department of Physics & Astronomy, University of British Columbia（不列颠哥伦比亚大学物理与天文学系）；RMIT University（皇家墨尔本理工大学）；Università Cattolica del Sacro Cuore（天主教大学）
本文利用偏振分辨多维相干光谱直接测量欠掺杂 Bi-2212 费米面不同区域的相干动力学，发现超导相中节点区激发与约 1.6 eV 电子激发反相关且相干超过 44 fs，而反节点区快速退相干，揭示了节点涨落受保护并可能维持高温超导量子相干行为。
Charge and current orders in the spin-fermion model with overlapping hot spots
近几年来，对低掺杂铜氧化物的实验研究揭示了赝能隙态中的各种破缺现象。电荷密度波、$C_{4}$旋转对称性破缺以及时间反演对称性破缺都在几个铜酸盐家族中被观察到。在这方面，多个非超导订单出现的理论模型是特别感兴趣的。我们考虑最近引入的（Phys. Rev. B 93，085131（2016））自旋费米子模型，在费米表面上具有重叠的“热点”。重点对粒子-空穴不稳定性，我们得到了一个丰富的相图与化学势相对于色散在$(0,π);\;(π,0)$和费米面曲率的波腹区域的控制参数。我们发现d波Pomeranchuk不稳定性，d-形状因子电荷密度波以及相称和不相称的交错键电流相类似的d-密度波状态的证据。发现曲率对电流阶数有促进作用。考虑到适当的参数范围，我们讨论了我们的结果与赝隙态和无公度磁相的关系。
