scholarly journals Wide applicability of high- Tc pairing originating from coexisting wide and incipient narrow bands in quasi-one-dimensional systems

2018 ◽  
Vol 97 (1) ◽  
Author(s):  
Karin Matsumoto ◽  
Daisuke Ogura ◽  
Kazuhiko Kuroki
Keyword(s):  
High Tc ◽  
One Dimensional ◽  
Wide Applicability ◽  
Narrow Bands

Intergrowth of modulated structures in high Tc Bi-Sr-Ca-Cu-O superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 76-77
Author(s):  
A.Q. He ◽  
G.W. Qiao ◽  
J. Zhu ◽  
H.Q. Ye
Keyword(s):  
Twin Structure ◽  
Modulated Structure ◽  
High Tc ◽  
One Dimensional ◽  
Lattice Constants ◽  
Superconducting Phases ◽  
Modulated Structures ◽  
Layer Structures

Since the first discovery of high Tc Bi-Sr-Ca-Cu-O superconductor by Maeda et al, many EM works have been done on it. The results show that the superconducting phases have a type of ordered layer structures similar to that in Y-Ba-Cu-O system formulated in Bi2Sr2Can−1CunO2n+4 (n=1,2,3) (simply called 22(n-1) phase) with lattice constants of a=0.358, b=0.382nm but the length of c being different according to the different value of n in the formulate. Unlike the twin structure observed in the Y-Ba-Cu-O system, there is an incommensurate modulated structure in the superconducting phases of Bi system superconductors. Modulated wavelengths of both 1.3 and 2.7 nm have been observed in the 2212 phase. This communication mainly presents the intergrowth of these two kinds of one-dimensional modulated structures in 2212 phase.

Synthesis of One-dimensional Nano-sized Defects in High Tc Superconductor

2006 ◽  
Author(s):  
In-Gann Chen ◽  
Maw-Kuen Wu ◽  
Shih-Yun Chen
Keyword(s):  
High Tc ◽  
One Dimensional ◽  
High Tc Superconductor

Computer Simulation of Pulsed Laser Ablation for YBaCuO Superconducting Films

1990 ◽  
Vol 191 ◽  
Author(s):  
Toshiyuki Nakamiya ◽  
Kenji Ebihara ◽  
P. K. John ◽  
B. Y. Tong
Keyword(s):  
Thin Films ◽  
Excimer Laser ◽  
Laser Energy ◽  
Pulsed Laser ◽  
The Finite Element Method ◽  
High Tc ◽  
One Dimensional ◽  
Incident Laser Energy ◽  
Krf Excimer Laser ◽  
Pulsed Laser Irradiation

ABSTRACTThe dynamics of melting and ablation of high Tc YBa2Cu3O7-x superconducting thin films flashed by a pulsed KrF excimer laser(λ=248nm) or a pulsed Nd-YAG laser (λ =1.06μ m) were studied numerically. The fundamental model during a pulsed laser irradiation was a one-dimensional heat conduction equation. The finite element method was applied to solve the equation including the temperature dependence of the thermal conductivity of YBaCuO thin films. In addition, the microstructure of YBa2Cu3O7-x bulk(l.5mm thick) flashed by a pulsed XeCl excimer laser (λ =308nm) was investigated by scanning electron microscopy (SEM) in order to estimate the threshold incident laser energy density for surface melting and ablation. The good agreements between the numerical calculations and the experimental results were obtained.

scholarly journals MECHANISM OF HIGH-Tc SUPERCONDUCTIVITY BASED MAINLY ON TUNNELING MEASUREMENTS IN CUPRATES

2005 ◽  
Vol 19 (16) ◽  
pp. 743-770 ◽  
Author(s):  
A. MOURACHKINE
Keyword(s):  
Tunneling Spectroscopy ◽  
Phase Coherence ◽  
Spin Fluctuations ◽  
Cooper Pairs ◽  
High Tc ◽  
High Tc Superconductivity ◽  
One Dimensional ◽  
Topological Excitations ◽  
Discrete Breathers

The main purpose of this brief review is to present a sketch of the mechanism of high-Tc superconductivity based mainly on tunneling measurements in cuprates. In the review, we shall mostly discuss tunneling spectroscopy in Bi 2 Sr 2 CaCu 2 O 8. Analysis of the data shows that the Cooper pairs in cuprates are topological excitations (e.g. quasi-one-dimensional bisolitons, discrete breathers etc.), and the phase coherence among the Cooper pairs appears due to spin fluctuations.

THE ROLE OF QUASI-ONE-DIMENSIONAL STRUCTURES IN HIGH-Tc SUPERCONDUCTIVITY

1989 ◽  
Vol 03 (03) ◽  
pp. 427-439 ◽  
Author(s):  
N. M. BOGOLIUBOV ◽  
V. E. KOREPIN
Keyword(s):  
Critical Temperature ◽  
Critical Exponents ◽  
Electron Tunneling ◽  
Dimensional System ◽  
Cooper Pairs ◽  
High Tc ◽  
Mean Values ◽  
One Dimensional ◽  
The One

The critical exponents describing the decrease of correlation functions on long distances for the one-dimensional Hubbard model is obtained. The behaviour of correlators shows that Cooper pairs of electrons are formed. The electron tunneling between the chains leads to the existence of the anomalous mean values and to the superconductive current. The anisotropy of the quasi-one-dimensional system leads to the rise of critical temperature T c .

QUANTUM NETWORK SIMULATIONS OF HIGH Tc CERAMIC SUPERCONDUCTORS

1988 ◽  
Vol 02 (06) ◽  
pp. 1399-1405 ◽  
Author(s):  
MARK JEFFERY ◽  
CHARLES GREEN ◽  
SOMDEV TYAGI ◽  
R. GILMORE
Keyword(s):  
Quantum Network ◽  
High Tc ◽  
One Dimensional ◽  
Ceramic Superconductors ◽  
Weak Magnetic Fields ◽  
Weakly Coupled ◽  
S Matrix ◽  
Network Simulations ◽  
Quantum Network Model ◽  
Absorption Measurements

Microwave absorption measurements of the high T c ceramic superconductors reveal reproducible features in weak magnetic fields. These features are qualitatively explained by a quantum network model of these superconducting oxides. The ceramic superconductors are modeled as a set of one-dimensional wires weakly coupled at random nodes. The magnetoconductance, magnetization and susceptibility are computed from the network S-matrix.

Fully Legendre Spectral Galerkin Algorithm for Solving Linear One-Dimensional Telegraph Type Equation

2019 ◽  
Vol 16 (08) ◽  
pp. 1850118 ◽  
Author(s):  
E. H. Doha ◽  
W. M. Abd-Elhameed ◽  
Y. H. Youssri
Keyword(s):  
Error Analysis ◽  
Boundary Conditions ◽  
Numerical Algorithm ◽  
Type Equation ◽  
High Accuracy ◽  
Basis Functions ◽  
Structured Matrices ◽  
One Dimensional ◽  
Wide Applicability ◽  
Careful Investigation

In this paper, we analyze and implement a new efficient spectral Galerkin algorithm for handling linear one-dimensional telegraph type equation. The principle idea behind this algorithm is to choose appropriate basis functions satisfying the underlying boundary conditions. This choice leads to systems with specially structured matrices which can be efficiently inverted. The proposed numerical algorithm is supported by a careful investigation for the convergence and error analysis of the suggested approximate double expansion. Some illustrative examples are given to demonstrate the wide applicability and high accuracy of the proposed algorithm.

Narrow bands and electronic structure in unconventional high-TC superconductors

2002 ◽  
Vol 127 (1-2) ◽  
pp. 117-123
Author(s):  
E. Cappelluti ◽  
C. Grimaldi ◽  
L. Pietronero ◽  
S. Strässler
Keyword(s):  
Electronic Structure ◽  
High Tc Superconductors ◽  
High Tc ◽  
Narrow Bands

Synthesis and Properties of a New Kind of One-Dimensional Conductors. 2. Extended Hückel Calculations on the Energy Band Structure

1979 ◽  
Vol 34 (8) ◽  
pp. 986-992 ◽  
Author(s):  
Friedrich Franz Seelig
Keyword(s):  
Necessary Condition ◽  
Energy Bands ◽  
One Dimensional ◽  
Bridging Ligand ◽  
New Type ◽  
Quantitative Results ◽  
Preceding Communication ◽  
Extended Hückel Calculations ◽  
Narrow Bands ◽  
Broad Energy

AbstractThe co-ordination polymer of tetrazaporphin (TAP) with a transition metal, say FeII , in its center and acetylide anion, C22⊖ , as an axial bidentate bridging ligand is taken as a model sub-stance for the new type of one-dimensional conductors introduced in the preceding communication of this series. Although the monomer shows D4h symmetry, this is reduced to C4v for arbitrary kz -values of the Bloch functions of the first Brillouin zone. From the irreducible representations a1, a2, b1, b2, and e only a1 and e have contributions from all components, namely TAP2⊖ , Fe2⊕ and C22⊖, so that for these races broad energy bands can be expected. The a2, b1, and b2 MOs of the TAP-FeII subunits are separated fairly well and have no counterparts in the C22⊖ bridges so that very narrow bands should arise. This is confirmed by an EH calculation. Unexpectedly the a1 bonds which have contributions from the σ-MOS of C22⊖ are broader than the e-bands which contain the two crossed π-MO systems of C22⊖ . The quantitative results of the nearly self-consistent iterative EH calculation indicate overlap of the energy bands near the Fermi level and fulfill thus one necessary condition for metal-like electrical conductivity.

Sign in / Sign up

Export Citation Format

Share Document