Anomalous asymmetry of the Fermi surface in the YBa2Cu4O8 high temperature superconductor revealed by Angle Resolved Photoemission Spectroscopy
Takeshi Kondo, R. Khasanov, Y. Sassa, A. Bendounan, S. Pailhes, J. Chang, J. Mesot, H. Keller, N. D. Zhigadlo, M. Shi, S. M. Kazakov, J. Karpinski, A. Kaminski
We use microprobe Angle-Resolved Photoemission Spectroscopy to study the Fermi surface and band dispersion of the CuO2 planes in the high temperature superconductor, YBa2Cu4O8. We find a strong in-plane asymmetry of the electronic structure between directions along a and b axes. The saddle point of the antibonding band lies at a significantly higher energy in the a direction (pi,0) than the b direction (0,pi), whereas the bonding band displays the opposite behavior. We demonstrate that the abnormal band shape is due to a strong asymmetry of the bilayer band splitting, likely caused by a non-trivial hybridization between the planes and chains. This asymmetry has an important implication for interpreting key properties of the Y-Ba-Cu-O (YBCO) family, especially the superconducting gap, transport and results of inelastic neutron scattering.
Fermi surfaces and orbital polarization in superconducting CeO$_{0.5}$F$_{0.5}$BiS$_{2}$ revealed by angle-resolved photoemission spectroscopy
利用偏振相关角分辨光电子能谱(ARPES)研究了BiSPDMATHABMM基CeO $_{0.5}$ F $_{0.5}$ BiS $_2$超导体的电子结构,并成功地阐明了费米面上的轨道特征.在X点周围的矩形费米口袋中,平行于$k_y$方向的直线部分由Bi $6p_x$特征主导。轨道极化表明BiS $_2$系统的准一维电子结构。此外,四边形排列的Bi上的扭曲可以引起带Jahn-Teller效应。
Nematicity in the pseudogap state of cuprate superconductors revealed by angle-resolved photoemission spectroscopy
赝能隙的性质及其与超导电性的关系是铜氧化物超导体的核心问题之一。最近,一种可能的情况已经提出,赝能隙状态是一个独特的阶段,其特征在于自发的旋转对称性破缺称为“向列性”的基础上的运输和磁化率测量,其中的对称性破缺被观察到低于赝能隙温度$T^*$。在这里,我们报告了一个温度依赖的ARPES研究的向列性在轻微过掺杂的Bi ${}_{1.7}$ Pb ${}_{0.5}$ Sr ${}_{1.9}$ CaCu ${}_2$ O ${}_{8+δ}$沿Cu-O键方向施加的单轴应变触发。虽然向列性增强的赝隙状态,在以前的研究中,它被抑制在超导状态。这些结果表明赝能隙态具有自发旋转对称破缺的特征,向列性可能与超导性竞争。这些新的实验发现可能为赝能隙的性质及其与超导电性的关系提供线索。
Disappearance of Superconductivity and a Concomitant Lifshitz Transition in Heavily-Overdoped Bi2Sr2CuO6 Superconductor Revealed by Angle-Resolved Photoemission Spectroscopy
Unusual Fermi surface nesting in parent compounds of iron arsenic high temperature superconductors revealed by Angle Resolved Photoemission Spectroscopy
Localized and mixed valence state of Ce $4f$ in superconducting and ferromagnetic CeO$_{1-x}$F$_{x}$BiS$_{2}$ revealed by x-ray absorption and photoemission spectroscopy
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。
Inhomogeneous reduction-annealing effects on the electron-doped cuprate superconductor revealed by micro-focused angle-resolved photoemission spectroscopy
Quasiparticles and Energy Scaling in Bi$_2$Sr$_2$Ca$_{n-1}$Cu$_n$O$_{2n+4}$ ($\it{n}$=1-3): Angle-Resolved Photoemission Spectroscopy
对Bi系高{ \it T $_c$ }超导体(Bi $_2$ Sr $_2$ Ca $_{n-1}$ Cu $_n$ O $_{2n+4}$,$\it{n}$ =1-3)进行了角分辨光电子能谱(ARPES)研究。我们在三层化合物的费米能级上发现了尖锐的准粒子峰和赝能隙。通过对三种化合物的比较,揭示了超导和赝能隙行为的特征能与最大值{ \it T $_c$ }成比例的普遍规律。
Anomalous contribution to the nematic electronic states from the structural transition in FeSe revealed by time- and angle-resolved photoemission spectroscopy
Hidden itinerant-spin phase in heavily-overdoped La2-xSrxCuO4 revealed by dilute Fe doping: A combined neutron scattering and angle-resolved photoemission study
Orbital-dependent electron correlation effect on the two- and three-dimensional Fermi surfaces in KFe2As2 revealed by angle-resolved photoemission spectroscopy
Coexistence of Two Sharp-Mode Couplings and Their Unusual Momentum Dependence in the Superconducting State of Bi2Sr2CaCu2O8+d Superconductor Revealed by Laser-Based Angle-Resolved Photoemission
Common Fermi Surface Topology and Nodeless Superconducting Gap in K0.68Fe1.79Se2 and (Tl0.45K0.34)Fe1.84Se2 Superconductors Revealed from Angle-Resolved Photoemission Spectroscopy
Electronic Structure and Superconducting Gap of HgBa$_2$Ca$_2$Cu$_3$O$_{8+δ}$ Revealed by Laser-Based Angle-Resolved Photoemission Spectroscopy
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所凝聚态物理国家实验室);University of Chinese Academy of Sciences(中国科学院大学);Technical Institute of Physics and Chemistry, Chinese Academy of Sciences(中国科学院化学物理研究所);Songshan Lake Materials Laboratory(松山湖材料实验室)
Detailed Electronic Structure of the Three-Dimensional Fermi Surface and its Sensitivity to Charge Density Wave Transition in ZrTe3 Revealed by High Resolution Laser-Based Angle-Resolved Photoemission Spectroscopy
Absence of Superconductivity in the "hole-doped" Fe pnictide Ba(Fe$_{1-x}$Mn$_{x}$)$_{2}$As$_{2}$: Photoemission and X-ray Absorption Spectroscopy Studies
本文用光电子能谱和X射线吸收谱研究了Ba(Fe $_{1-x}$ Mn $_{x}$)$_{2}$ As $_{2}$($x$ =0.08)的电子结构。随着温度的降低,从顺磁相到反铁磁相的转变,清楚地观察到角分辨光电子能谱。XAS结果表明,取代的Mn原子形成了强杂化基态。Mn $L_{3}$边缘的共振光电子能谱表明Mn的3d部分态密度分布在费米能级以下2-13 eV的宽能量范围内($E_F$),在$E_F$附近贡献很小.这表明,尽管Mn 3d As $4p$杂化很强,但掺杂Mn 3 $d$态仍是局域化的,并由于原位库仑和交换相互作用而分裂成占据和未占据的部分. Ba(Fe $_{1-x}$ Mn $_{x}$)$_{2}$ As $_{2}$中不存在超导电性可以归因于FeAs平面中不存在载流子掺杂,以及Mn杂质对反铁磁有序的强稳定性。
Angle-resolved photoemission spectroscopy of Na-doped Ca2CuO2Cl2 single crystals: Fingerprints of a magnetic insulator in a heavily underdoped superconductor
Orbital Characters Determined from Fermi Surface Intensity Patterns using Angle-Resolved Photoemission Spectroscopy
为了确定铁基超导体Ba $_{0.6}$ K $_{0.4}$ Fe $_{2}$ As $_{2}$和FeSe $_{0.45}$ Te $_{0.55}$的各种费米面口袋上的轨道特征,本文介绍了一种计算光电发射矩阵元的方法。我们比较我们的模拟与各种实验配置的光束方向和光偏振的实验数据。我们发现,从角度分辨的光电子能谱测量费米表面映射和能量-动量图沿高对称线显示的光电子强度图案表现出不对称性携带宝贵的信息探测的状态的性质,信息被破坏后的数据对称化过程中经常进行的角度分辨的光电子能谱数据的分析。我们的模拟结果与费米面一致,费米面主要来源于这些材料中的$d_{xy}$、$d_{xz}$和$d_{yz}$轨道。
Identification of Nodal Kink in Electron-Doped (Nd$_{1.85}$Ce$_{0.15}$)CuO$_4$ Superconductor from Laser-Based Angle-Resolved Photoemission Spectroscopy
对电子掺杂的(Nd $_{1.85}$ Ce $_{0.15}$)CuO $_4$高温超导体进行了高分辨激光角分辨光电子能谱测量。我们揭示了一个明确的扭结在$\sim$ 60毫电子伏的色散沿(0,0)-($π$,$π$)节方向,伴随着峰-谷-驼峰功能的光电子能谱。这表明,在电子掺杂的超导体中,节点电子与集体激发(玻色子)耦合,声子是最有可能的玻色子候选者。这一发现建立了一个普遍性的节点电子耦合在空穴和电子掺杂的高温铜氧化物超导体。
Doping Evolution of Nodal Electron Dynamics in Trilayer Cuprate Superconductor Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10+δ}$ Revealed by Laser-Based Angle-Resolved Photoemission Spectroscopy
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
Extraction of Electron Self-Energy and Gap Function in the Superconducting State of Bi_2Sr_2CaCu_2O_8 Superconductor via Laser-Based Angle-Resolved Photoemission
Anomalous doping evolution of nodal dispersion revealed by in-situ ARPES on continuously doped cuprates
利用原位角分辨光电子能谱研究了高温超导体Bi $_2$ Sr $_2$ CaCu $_2$ O $_{8+x}$连续掺杂表面结色散的系统掺杂演化.我们发现,节点色散有三个部分分开的两个扭结,位于~10 meV和大约70 meV,分别。这三个段具有不同的带速和不同的掺杂依赖性。特别是,高能量段的速度随着掺杂水平的降低而单调增加,甚至可以超过裸带速度。我们建议,电子分馏是一个可能的原因,这种异常的节点色散,甚至可能发挥关键作用,在理解的奇特性质的铜酸盐。