Motivated by neutron scattering experiments in the high-$T_c$ cuprates, we propose the two-component spin-fermion model as a minimal phenomenological model which has both local spins and itinerant fermions as independent degrees of freedom. Our calculations of the dynamic spin correlation function provide a successful description of the puzzling neutron experiment data and show that: (1) the upward dispersion branch of magnetic excitations is mostly due to the local spin excitations; (2) the downward dispersion branch is from collective particle-hole excitations of fermions; and (3) the resonance mode is a mixture of both degrees of freedom. Using the same model with the same set of parameters we calculated the renormalized quasiparticle dispersion and successfully reproduced one of the key features of the angle resolved photoemission spectroscopy (ARPES) experiments, i.e., the high energy kink structure in the fermion quasiparticle dispersion, hence further support the two component spin-fermion phenomenology.
The pursuit of a comprehensive understanding of the dynamical nature of intertwined orders in quantum matter has fueled the development of several new experimental techniques, including time- and angle-resolved photoemission spectroscopy (TR-ARPES). In this regard, the study of copper-oxide high-temperature superconductors, prototypical quantum materials, has furthered both the technical advancement of the experimental technique, as well as the understanding of their correlated dynamical properties. Here, we provide a brief historical overview of the TR-ARPES investigations of cuprates, and re…
Extremely Correlated Fermi Liquid Description of Normal State ARPES in Cuprates
用角分辨光电子能谱学(ARPES)测量的高温超导铜氧化物正常态单粒子谱函数,被认为是反常的,也是理解的关键。在这里,我们表明,一个前所未有的详细描述的数据所产生的光谱函数的极其相关的费米液态的t-J模型最近提出的Shastry。本说明书包括关于最佳掺杂的Bi $_2$ Sr $_2$ CaCu $_2$ O $_{8+δ}$的激光和常规同步加速器ARPES数据,以及关于La $_{1.85}$ Sr $_{0.15}$ CuO $_4$材料的常规同步加速器ARPES数据。{ \em它适用于具有相同物理参数值的所有数据集},满足粒子求和规则,并成功解决了色散中两个广泛讨论的“扭结”异常。
Influence of the Third Dimension of Quasi-Two-Dimensional Cuprate Superconductors on Angle-Resolved Photoemission Spectra
角分辨光电子能谱(ARPES)在分析严格的二维(2D)材料时表现出显着的简化,但即使是最各向异性的物理系统也显示出一些残余的三维性。在这里,我们演示了如何第三个维度体现在准二维材料的ARPES光谱考虑的例子,铜酸盐铋$_2$锶$_2$钙铜$_2$ O $_{8}$(Bi 2212)。胞间,层间跳跃,这是负责$k_z$色散的频带,被发现诱导一个不可约的扩大的ARPES线的形状与特征依赖于面内动量$k_\parallel$。我们的研究表明,ARPES线型可以提供一个直接的光谱窗口,通过检测这种新的增宽机制,建立在材料中的相干c轴电导率的存在,并承担通过ARPES实验在新材料中的2D到3D交叉和赝能隙和条纹物理的理解。
The inelastic neutron scattering spectrum in cuprate superconductors is discussed on the basis of the itinerant-localized duality model for strongly correlated electrons. In Appendix the consistency with recent rigorous theoretical result on ARPES is discussed.
We study the systematic doping evolution of nodal dispersions by in-situ angle-resolved photoemission spectroscopy on the continuously doped surface of a high-temperature superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$. We reveal that the nodal dispersion has three segments separated by two kinks, located at ~10 meV and roughly 70 meV, respectively. The three segments have different band velocities and different doping dependence. In particular, the velocity of the high-energy segment increases monotonically as the doping level decreases and can even surpass the bare band velocity. We propose tha…
Unified description of cuprate superconductors by fractionalized electrons emerging from integrated analyses of photoemission spectra and quasiparticle interference
Sophia University(上智大学);RIKEN Center for Emergent Matter Science(理化学研究所物质结构科学中心);National Institute for Materials Science(国立材料研究所);RIKEN Center for Computational Science(理化学研究所计算科学中心);Schrödinger Inc.(薛定谔公司);University of Tokyo(东京大学);Ames National Laboratory(艾姆斯国家实验室);Iowa State University(爱荷华州立大学);ISSP, University of Tokyo(东京大学国际超导材料研究中心);Kyoto University(京都大学)
One of the most puzzling problems of high temperature cuprate superconductor is the pseudogap phase(PG) at temperatures above the superconducting transition temperature in the underdoped regime. The PG phase is found by the angle-resolved photoemission spectra(ARPES) to have a gap at some regions in momentum space and a fraction of Fermi surface remained, known as Fermi arcs. The arc turns into a d-wave SC gap with a node below the SC transition temperature. Here, by studying a strongly correlated model at low temperatures, we obtained a phase characterized by two kinds of pairing order parame…
We show that electron pairing is indispensable for the development of the leading edge gap as observed in ARPES measurement in the underdoped cuprates, even though clear evidence for the violation of the particle-hole symmetry is found in the electron spectrum. To support this assertion, we studied the electron spectrum under the scattering of diffusive antiferromagnetic(AF) spin fluctuation, which is thought to be a major candidate for a competing order in the competing order scenario of the pseudogap phenomena. We find that the Fermi level crossing along the M=$(π,0)$ to X=$(π,π)$ line can o…
The cuprate superconductors distinguish themselves from the conventional superconductors in that a small variation in the carrier doping can significantly change the superconducting transition temperature (T_c), giving rise to a superconducting dome where a pseudogap (ref. 1,2) emerges in the underdoped region and a Fermi liquid appears in the overdoped region. Thus a systematic study of the properties over a wide doping range is critical for understanding the superconducting mechanism. Here, we report a new technique to continuously dope the surface of Bi2Sr2CaCu2O8+x through an ozone/vacuum …
In the course of seeking the microscopic mechanism of superconductivity in cuprate high temperature superconductors, the pseudogap phase\textemdash the very abnormal 'normal' state on the hole-doped side\textemdash has proven to be as big of a quandary as superconductivity itself. Angle-resolved photoemission spectroscopy (ARPES) is a powerful tool for assessing the momentum-dependent phenomenology of the pseudogap, and recent technological developments have permitted a more detailed understanding. This report reviews recent progress in understanding the relationship between superconductivity …
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。
We utilized high-resolution resonant angle-resolved photoemission spectroscopy (ARPES) to study the band structure and hybridization effect of the heavy-fermion compound Ce2IrIn8. We observe a nearly flat band at the binding energy of 7 meV below the coherent temperature Tcoh ~ 40 K, which characterizes the electrical resistance maximum indicating the onset temperature of hybridization. However, the Fermi vector kF and the Fermi surface (FS) volume have little change around Tcoh, challenging the widely believed evolution from a high-temperature small FS to a low-temperature large FS. Our exper…
Hybridization of Bogoliubov-quasiparticles between adjacent CuO$_2$ layers in the triple-layer cuprate Bi$_2$Sr$_2$Ca$_2$Cu$_3$O$_{10+δ}$ studied by ARPES
Occurrence of Fermi Pockets without Pseudogap Hypothesis and Clarification of the Energy Distribution Curves of Angle-Resolved Photoemission Spectroscopy in Underdoped Cuprate Superconductors
The electron dynamics in the CuO chains has been elusive in Y-Ba-Cu-O cuprate systems by means of standard angle-resolved photoemission spectroscopy (ARPES); cleaved sample exhibits areas terminated by both CuO-chain or BaO layers, and the size of a typical beam results in ARPES signals that are superposed from both terminations. Here, we employ spatially-resolved ARPES with submicrometric beam (nano-ARPES) to reveal the surface-termination-dependent electronic structures of the double CuO chains in YBa$_2$Cu$_4$O$_8$. We present the first observation of sharp metallic dispersions and Fermi su…
A microscopic basis is provided for the spin-fermion model used to describe the physics of the underdoped cuprates. In this way, a spin-fermion coupling is shown to take care of the local no double occupancy constraint, which is ignored in the weakly coupled regime. This ingredient is proved to be essential to capture the physics of strong correlations, however. We elaborate further on our recent proposal for the strong-coupling version of the spin-fermion model that may prove to be the correct starting point to deal with the strong correlation physics displayed by the underdoped cuprates.
Using angle-resolved photoemission spectroscopy it is revealed that in the vicinity of optimal doping the electronic structure of La2-xSrxCuO4 cuprate undergoes an electronic reconstruction associated with a wave vector q_a=(pi, 0). The reconstructed Fermi surface and folded band are distinct to the shadow bands observed in BSCCO cuprates and in underdoped La2-xSrxCuO4 with x <= 0.12, which shift the primary band along the zone diagonal direction. Furthermore the folded bands appear only with q_a=(pi, 0) vector, but not with q_b= (0, pi). We demonstrate that the absence of q_b reconstruction i…
广泛的ARPES和低能量非弹性中子散射研究铜氧化物超导体可以成功地描述使用弱耦合理论,其中准粒子在正方形晶格上通过标量和自旋相关的有效相互作用。在本文中,我们指出在Bi $_2$ Sr $_2$ Ca $_{1-x}$ Y $_x$ Cu $_2$ O $_8$(Bi 2212)中,两种探针都与主要的近邻海森堡相互作用相一致。我们讨论了高$T_c$超导机制的这一发现的影响。