PHOTOEMISSION STUDY OF THE INTRA-UNIT-CELL COUPLING IN A TRILAYER CUPRATE

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1691-1696 ◽  
Author(s):  
D. L. FENG ◽  
H. EISAKI ◽  
K. M. SHEN ◽  
A. DAMASCELLI ◽  
C. KIM ◽  
...  
Keyword(s):  
Electronic Structures ◽  
Cuprate Superconductors ◽  
Single Layer ◽  
Interlayer Coupling ◽  
Unit Cell ◽  
Photoemission Spectroscopy ◽  
Cell Coupling ◽  
Lineshape Analysis ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Photoemission Study

The electronic structures of the nearly optimally doped single-layer, bilayer and trilayer Bi-based cuprates are investigated by angle-resolved photoemission spectroscopy. A lineshape analysis of data taken for different photon energies indicates that the interlayer coupling within the trilayer is not stronger than its counterpart in the bilayer system. This suggests that the higher T c of the trilayer cuprate superconductors is not due to an enhancement of the coupling strength between the neighboring CuO2 planes within each unit cell.

scholarly journals Emergent flat band electronic structure in a VSe2/Bi2Se3 heterostructure

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Turgut Yilmaz ◽  
Xiao Tong ◽  
Zhongwei Dai ◽  
Jerzy T. Sadowski ◽  
Eike F. Schwier ◽  
...  
Keyword(s):  
Dirac Point ◽  
Electronic States ◽  
Quantum States ◽  
Photoemission Spectroscopy ◽  
Flat Band ◽  
Strongly Correlated ◽  
Dirac Cone ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Topological Materials ◽  
Photoemission Study

AbstractFlat band electronic states are proposed to be a fundamental tool to achieve various quantum states of matter at higher temperatures due to the enhanced electronic correlations. However, materials with such peculiar electronic states are rare and often rely on subtle properties of the band structures. Here, by using angle-resolved photoemission spectroscopy, we show the emergent flat band in a VSe2 / Bi2Se3 heterostructure. Our photoemission study demonstrates that the flat band covers the entire Brillouin zone and exhibits 2D nature with a complex circular dichroism. In addition, the Dirac cone of Bi2Se3 is not reshaped by the flat band even though they overlap in proximity of the Dirac point. These features make this flat band distinguishable from the ones previously found. Thereby, the observation of a flat band in the VSe2 / Bi2Se3 heterostructure opens a promising pathway to realize strongly correlated quantum effects in topological materials.

scholarly journals Observation of small Fermi pockets protected by clean CuO2 sheets of a high-Tc superconductor

Science ◽  
2020 ◽  
Vol 369 (6505) ◽  
pp. 833-838 ◽  
Author(s):  
So Kunisada ◽  
Shunsuke Isono ◽  
Yoshimitsu Kohama ◽  
Shiro Sakai ◽  
Cédric Bareille ◽  
...  
Keyword(s):  
Cuprate Superconductors ◽  
Parent Compound ◽  
High Critical Transition Temperature ◽  
Photoemission Spectroscopy ◽  
Hole Doping ◽  
Quantum Oscillation ◽  
Critical Transition Temperature ◽  
High Tc ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Antiferromagnetic Ordering

In cuprate superconductors with high critical transition temperature (Tc), light hole-doping to the parent compound, which is an antiferromagnetic Mott insulator, has been predicted to lead to the formation of small Fermi pockets. These pockets, however, have not been observed. Here, we investigate the electronic structure of the five-layered Ba2Ca4Cu5O10(F,O)2, which has inner copper oxide (CuO2) planes with extremely low disorder, and find small Fermi pockets centered at (π/2, π/2) of the Brillouin zone by angle-resolved photoemission spectroscopy and quantum oscillation measurements. The d-wave superconducting gap opens along the pocket, revealing the coexistence between superconductivity and antiferromagnetic ordering in the same CuO2 sheet. These data further indicate that superconductivity can occur without contribution from the antinodal region around (π, 0), which is shared by other competing excitations.

Electronic structures of layered Ta2NiS5 single crystals revealed by high-resolution angle-resolved photoemission spectroscopy

2018 ◽  
Vol 6 (15) ◽  
pp. 3976-3981 ◽  
Author(s):  
Kejun Mu ◽  
Haiping Chen ◽  
Yuliang Li ◽  
Yingying Zhang ◽  
Pengdong Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Single Crystals ◽  
Electronic Structures ◽  
Photoemission Spectroscopy ◽  
One Dimensional ◽  
Angle Resolved Photoemission Spectroscopy

Using high-resolution angle-resolved photoemission spectroscopy (ARPES), we systematically studied the electronic structures of quasi-one-dimensional (1D) ternary material Ta2NiS5 single crystals.

VALENCE ELECTRONIC STRUCTURE OF OXYGEN-MODIFIED α-Mo2C(0001) SURFACE: ANGLE-RESOLVED PHOTOEMISSION STUDY

2006 ◽  
Vol 13 (02n03) ◽  
pp. 185-190
Author(s):  
M. KATO ◽  
K. OZAWA ◽  
T. SATO ◽  
K. EDAMOTO
Keyword(s):  
Electron Spectroscopy ◽  
Oxygen Adsorption ◽  
Photoemission Spectroscopy ◽  
Metallic State ◽  
Low Energy Electron Diffraction ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Peak Intensity ◽  
Low Energy Electron ◽  
Photoemission Study ◽  
Surface Angle

Adsorption of oxygen on α- Mo 2 C (0001) is investigated with Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and angle-resolved photoemission spectroscopy (ARPES) utilizing synchrotron radiation. It is found that C KLL Auger peak intensity does not change during O 2 exposure, indicating that the depletion of C atoms does not proceed. It is deduced from ARPES and LEED results that adsorbed oxygen atoms from a well-ordered (1 × 1) lattice on the α- Mo 2 C (0001) surface. The ARPES study shows that oxygen adsorption induces a peculiar state around Fermi level (E F ). Off-normal-emission measurements prove that the state is a half-filled metallic state.

Angle-Resolved Photoemission Spectroscopy Study of Topological Quantum Materials

2020 ◽  
Vol 50 (1) ◽  
pp. 131-153
Author(s):  
Chaofan Zhang ◽  
Yiwei Li ◽  
Ding Pei ◽  
Zhongkai Liu ◽  
Yulin Chen
Keyword(s):  
Electronic Structures ◽  
Photoemission Spectroscopy ◽  
Topological Invariants ◽  
New Materials ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Topological Quantum ◽  
Experimental Tool ◽  
Weyl Semimetals ◽  
Quantum Materials ◽  
Physical Phenomena

The recently discovered topological quantum materials (TQMs) have electronic structures that can be characterized by certain topological invariants. In these novel materials, the unusual bulk and surface electrons not only give rise to many exotic physical phenomena but also foster potential new technological applications. To characterize the unusual electronic structures of these new materials, investigators have used angle-resolved photoemission spectroscopy (ARPES) as an effective experimental tool to directly visualize the unique bulk and surface electronic structures of TQMs. In this review, we first give a brief introduction of TQMs and ARPES, which is followed by examples of the application of ARPES to different TQMs ranging from topological insulators to Dirac and Weyl semimetals. We conclude with a brief perspective of the current development of ARPES and its potential application in the study of TQMs.

UV Photoemission Study of Interfaces Related to Organic EL Devices

1997 ◽  
Vol 488 ◽  
Author(s):  
Kiyoshi Sugiyama ◽  
Kazuhiko Seki ◽  
Eisuke Ito ◽  
Yukio Ouchi ◽  
Hisao ISHII
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Electronic Structures ◽  
Organic Molecule ◽  
Negative Charge ◽  
Photoemission Spectroscopy ◽  
Level Shift ◽  
Vacuum Level ◽  
Organic Electroluminescent ◽  
Photoemission Study

AbstractInterfacial electronic structures related to organic electroluminescent (EL) devices were studied by UV photoemission spectroscopy (UPS). The two classes of interfaces studied were: (1) interfaces in a typical multilayer device AI/AIq3TPD/ITO, where Alq3 is tris(8-hydroxyquinolino)- aluminum, TPD is N,N×-diphenyl-NN×-(3-methylphenyl)- 1, 1‘-biphenyl-4,4’-diamine, and ITO is indium tin oxide, and (2) TTN/metals and TCNQ/metals interfaces, where TTN is tetrathianaphthacene and TCNQ is tetracyanoquinodimethane. The UPS studies of the specimen formed by the successive deposition of TPD, Alq3, and Al on ITO revealed interfacial energy diagrams, with the vacuum level shift of - 0.25 eV (downward) and - 0.1 eV (downward) at the TPD / ITO and the Alq3 / TPD interfaces, respectively. The deposition of TTN and TCNQ on metals showed opposite direction of the shift of the vacuum level, with the positive and negative charge at the vacuum side. This can be explained by considering the chargetransfer between the metal and the organic molecule, with these directions being consistent with the electron donating and accepting ability of these molecules.

High Resolution Photoelectron Study of the Optimum Oxygen Doping Levels in High Tc Superconductors

1993 ◽  
Vol 307 ◽  
Author(s):  
R. J. Kelley ◽  
X. C. Cai ◽  
Jian Ma ◽  
D. C. Larbalestier ◽  
M. Onellion
Keyword(s):  
High Resolution ◽  
Electronic Properties ◽  
Cuprate Superconductors ◽  
Underlying Mechanism ◽  
Oxygen Stoichiometry ◽  
Photoemission Spectroscopy ◽  
Standard Material ◽  
Resonant Photoemission ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Photoelectron Study

ABSTRACTThe materials and electronic properties of the new cuprate superconductors are critically dependent upon both the oxygen stoichiometry and annealing history of the material. Improving Jc, Tc, and determining the underlying mechanism of superconductivity depend on a better understanding of these effects. In the study of Bi2Sr2CaCu2O8-δ we have combined standard material characterization techniques with high resolution angle resolved photoemission spectroscopy and resonant photoemission spectroscopy to illuminate these issues. Specifically, we make high quality single crystals of BSCCO and then anneal in different atmospheres and pressures. We correlate this with c-axis resistivity, a, b-plane resistivity, and resonant photoemission spectroscopy. In this way we can explain the macroscopic transport properties in terms of the electronic properties of the material determined from photoemission. We find that we can change the c-axis resistivity from non-metallic to metallic by adding oxygen and that this correlates with increased oscillator strength in the c-axis direction at the Fermi level.

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