Electronic structure of BaNi$_2$P$_2$ observed by angle-resolved photoemission spectroscopy
S. Ideta, T. Yoshida, M. Nakajima, W. Malaeb, H. Kito, H. Eisaki, A. Iyo, Y. Tomioka, T. Ito, K. Kihou, C. H. Lee, Y. Kotani, K. Ono, S. K. Mo, Z. Hussain, Z. -… 展开作者
S. Ideta, T. Yoshida, M. Nakajima, W. Malaeb, H. Kito, H. Eisaki, A. Iyo, Y. Tomioka, T. Ito, K. Kihou, C. H. Lee, Y. Kotani, K. Ono, S. K. Mo, Z. Hussain, Z. -X. Shen, H. Harima, S. Uchida, A. Fujimori
用角分辨光电子能谱（ARPES）研究了BaNi $_2$ P $_2$在$T_c$ $\sim$ 2.5 K的超导转变.我们观察到空穴和电子费米面（FS）周围的布里渊区的中心和角落，分别和空穴FS的形状显着变化的光子能量，表明强的三维性。观测到的FS与能带结构计算和de Haas-van Alphen测量结果一致。在正常状态下估计的质量增强因子为$m^*$ / $m_b$ $\leq$ 2，表明与典型的铁-磷属元素化物超导体相比，电子相关性较弱。与BaNi $_2$ As $_2$相比，观察到Z点周围的类电子费米面，这可能与BaNi $_2$ P $_2$的较高的$T_c$有关。
英文摘要：
We have performed an angle-resolved photoemission spectroscopy (ARPES) study of BaNi$_2$P$_2$ which shows a superconducting transition at $T_c$ $\sim$ 2.5 K. We observed hole and electron Fermi surfaces (FSs) around the Brillouin zone center and corner, respectively, and the shapes of the hole FSs dramatically changed with photon energy, indicating strong three-dimensionality. The observed FSs are consistent with band-structure calculation and de Haas-van Alphen measurements. The mass enhancement factors estimated in the normal state were $m^*$/$m_b$ $\leq$ 2, indicating weak electron correlation compared to typical iron-pnictide superconductors. An electron-like Fermi surface around the Z point was observed in contrast with BaNi$_2$As$_2$ and may be related to the higher $T_c$ of BaNi$_2$P$_2$.
BaNi2As2 is a superconductor chemically related to the Fe-based superconductors, with a complex and poorly understood structural phase transition. We show based on first principles calculations that in fact there are two distinct competing structures. These structures are very different from electronic, transport and bonding points of view but are close in energy. These arise due to complex As bonding patterns and drive distortions of the Ni layers. This is supported by photoemission experiments. This leads to an interplay of electronic and structural behavior including induced anisotropic of …
We present the development of a high-precision sample-position-autocorrection system for photoemission experiments. A binocular vision method based on image pattern matching calculations was realized to track the sample position with an accuracy better than 1 \um, which was much smaller than the spot size of the incident laser. We illustrate the performance of the sample-position-autocorrection system with representative photoemission data on the topological insulator Bi$_2$Se$_3$ and an optimally-doped cuprate superconductor \Bi. Our method provides new possibilities for studying the temperat…
We review recent work on the theory for pump/probe photoemission spectroscopy of electron-phonon mediated superconductors in both the normal and the superconducting states. We describe the formal developments that allow one to solve the Migdal-Eliashberg theory in nonequilibrium for an ultrashort laser pumping field, and explore the solutions which illustrate the relaxation as energy is transferred from electrons to phonons. We focus on exact results emanating from sum rules and approximate numerical results which describe rules of thumb for relaxation processes. In addition, in the supercondu…
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。
Reply to Comment on Circular Dichroism in the Angle-Resolved Photoemission Spectrum of the High-Temperature Bi2Sr2CaCu2O8 Superconductor http://arxiv.org/abs/1004.1648
Angle-Resolved Photoemission Spectroscopy of the Antiferromagnetic Superconductor Nd1.87Ce0.13CuO4: Anisotropic Spin-Correlation Gap, Pseudogap, and the Induced Quasiparticle Mass Enhancement
Temperature dependence of the angle resolved photoemission spectra in the undoped cuprates: self-consistent approach to the t-J-Holstein model
我们开发了一种新的自洽方法来研究角分辨光电子能谱（ARPES）的一个洞的t-J-Holstein模型给出完美的协议与数字精确的Diagrammatic Monte Carlo数据在零温度下的所有制度的电子-声子耦合。推广到有限温度的方法，我们发现，在未掺杂的铜酸盐的ARPES的异常温度依赖性的解释合作的相互作用的耦合的孔的磁波动和强的电子-声子相互作用。
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。
Time- and angle-resolved photoemission spectroscopy has played an important role in revealing the non-equilibrium electronic structures of solid-state materials. The implementation of high harmonic generation to obtain a higher photon energy also allows us to investigate the wide Brillouin zone on a time scale below 100 fs. In this article, we review our recent studies using high-harmonic-generation-laser-based time- and angle-resolved photoemission spectroscopy to study a variety of quantum materials. We reveal many unprecedented phenomena in each system and highlight some representative resu…
Reply to "Comment on arXiv:1012.1484v1 Structural origin of apparent Fermi surface pockets in angle-resolved photoemission of Bi_2Sr_{2-x}La_xCuO_{6+δ} by King et al."
Techniques in time- and angle-resolved photoemission spectroscopy have facilitated a number of recent advances in the study of quantum materials. We review developments in this field related to the study of incoherent nonequilibrium electron dynamics, the analysis of interactions between electrons and collective excitations, the exploration of dressed-state physics, and the illumination of unoccupied band structure. Future prospects are also discussed.
We present a study of the tetragonal to collapsed-tetragonal transition of CaFe2As2 using angle-resolved photoemission experiments and dynamical mean field theory-based electronic structure calculations. We observe that the collapsed-tetragonal phase exhibits reduced correlations and a higher coherence temperature due to the stronger Fe-As hybridization. Furthermore, a comparison of measured photoemission spectra and theoretical spectral functions shows that momentum-dependent corrections to the density functional band structure are essential for the description of low-energy quasiparticle dis…
A recent article by Sassa et al. [Phys. Rev. B 91, 045114 (2015)] reports on a soft x-ray angle-resolved photoemission study of MgB2. The analysis and/or presentation of the collected data and the corresponding calculations appear to be partially inconsistent. The aim of this comment is to provide a guide to these inconsistencies and to discuss their influence on the presented conclusions.
Polarization-Dependent Three-Dimensional Angle-Resolved Photoemission Spectroscopy of BaFe$_{1.8}$Co$_{0.2}$As$_{2}$
我们利用偏振和光子能量相关的角度分辨光电子能谱研究了一种稍过掺杂的铁磷属元素化物超导体BaFe $_{1.8}$ Co $_{0.2}$ As $_{2}$的三维电子结构，包括布里渊区中心的轨道特征.观察到具有$d_{xz/yz}$和$d_{xy/x^2-y^2}$轨道的两个空穴费米面（FS），但是没有出现根据自旋涨落超导机制理论具有节点的$d_{z^2}$空穴FS。这些结果表明，在区域中心的孔FS处不会出现节点。
Dependence of Band Renormalization Effect on the Number of Copper-oxide Layers in Tl-based Copper-oxide Superconductor using Angle-resolved Photoemission Spectroscopy
The three-dimensional electronic structure and Ce 4f electrons of the heavy fermion superconductor CePt2In7 is investigated. Angle-resolved photoemission spectroscopy using variable photon energy establishes the existence of quasi-two and three dimensional Fermi surface topologies. Temperature-dependent 4d-4f on-resonance photoemission spectroscopies reveal that heavy quasiparticle bands begin to form at a temperature well above the characteristic (coherence) temperature T*. T* emergence may be closely related to crystal electric field splitting, particularly the low-lying heavy band formed by…
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。
Underlying Fermi surface of Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$ in two-dimensional momentum space observed by angle-resolved photoemission spectroscopy
我们已经进行了角分辨光电子能谱研究的双腿梯形系统Sr $_{14-x}$ Ca $_x$ Cu $_{24}$ O $_{41}$与$x$ = 0和11。由低能谱权映射确定的“底层费米面”表明了电子结构的准一维性质。对于$x$ =0，观察到由电荷密度波引起的能隙，并且随着Ca取代，能隙趋于闭合。即使在$x$ =11中也没有准粒子峰，这与二维高$T_c$铜酸盐相反，意味着与空穴结晶相关的强载流子局域化。
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。
Angle-resolved photoemission spectroscopy of Na-doped Ca2CuO2Cl2 single crystals: Fingerprints of a magnetic insulator in a heavily underdoped superconductor
