The investigation on anomalous isotope effect coefficient of LaSrCuO superconductor

2019 ◽  
Vol 33 (31) ◽  
pp. 1950379
Author(s):  
P. Mycharoen ◽  
P. Udomsamuthirun
Keyword(s):  
Experimental Data ◽  
Critical Temperature ◽  
Temperature Dependence ◽  
Isotope Effect ◽  
Weak Coupling ◽  
Numerical Results ◽  
Coupling Method ◽  
Density Of State ◽  
Van Hove Singularity ◽  
Weak Coupling Method

In this research, the anomalous isotope effect coefficient of LaSrCuO superconductor was investigated in the weak-coupling method. The constant and van Hove singularity density of state, pseudogap, and the form of pseudogap temperature dependence on critical temperature are included in our calculation. Finally, the numerical results are shown in comparison with the experimental data of LaSrCuO superconductor. We found that the van Hove singularity density of state and the inversely relation of pseudogap temperature and critical temperature can fit well with the anomalous isotope effect coefficient data of LaSrCuO superconductor.

Effect of pseudogap and van Hove singularity density of state on the isotope effect coefficient of superconductor

2018 ◽  
Vol 32 (11) ◽  
pp. 1850130 ◽  
Author(s):  
Thaipanya Chanpoom
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Critical Temperature ◽  
Isotope Effect ◽  
High Temperature Superconductors ◽  
Numerical Results ◽  
Density Of State ◽  
Van Hove Singularity

This research was to study the isotope effect coefficient of high temperature superconductors taking into account the pseudogap. We used the BCS-like model including the effect of the vHs density of state and pseudogap. The isotope effect coefficient was derived to the analytical and the approximation form. For the effect of vHs density of state, we found that the isotope effect coefficient increased as the critical temperature increased. For the pseudogap effect, as the critical temperature increased, the isotope effect coefficient decreased to the BCS value, 0.5. For the effect of the vHs density of state and pseudogap, we found that when the critical temperature increased, the isotope effect coefficient decreased. Finally, we showed our numerical results that can fit well with the experimental data of YBa[Formula: see text]La[Formula: see text]Cu3O[Formula: see text] and Y[Formula: see text]Pr[Formula: see text]Ba2Cu3O[Formula: see text] superconductors.

THEORY OF THE ISOTOPE EFFECT AND SUPERCONDUCTING TRANSITION TEMPERATURE IN HIGH-Tc OXIDES

2011 ◽  
Vol 25 (26) ◽  
pp. 2069-2078 ◽  
Author(s):  
A. BECHLAGHEM ◽  
D. BOURBIE
Keyword(s):  
Experimental Data ◽  
Transition Temperature ◽  
Fermi Level ◽  
Isotope Effect ◽  
Qualitative Agreement ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
Van Hove Singularity ◽  
High Tc ◽  
Analytical Expressions

Analytical expressions for the superconducting transition temperature Tc and the isotope coefficient α have been obtained for the case where the Fermi level is close to the van Hove singularity. In this approach, we consider two interactions, the first related to the phonons and the second relevant to the magnetic excitations. Our result shows that the isotope coefficient α decreases with the superconducting transition temperature Tc in qualitative agreement with experimental data.

Nanoparticles Size in Fe73.5Cu1Mo3Si13.5B9 Melt

2020 ◽  
Vol 861 ◽  
pp. 107-112
Author(s):  
Vladimir S. Tsepelev ◽  
Yuri N. Starodubtsev ◽  
Kai Ming Wu ◽  
Yekaterina A. Kochetkova
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficient ◽  
Critical Temperature ◽  
Temperature Dependence ◽  
Kinematic Viscosity ◽  
Arrhenius Equation ◽  
Reaction Rates ◽  
Mechanical Theory ◽  
Statistical Mechanical ◽  
Absolute Reaction

The size of the nanoparticles participating in the viscous flow and the diffusion coefficient were calculated using statistical mechanical theory of absolute reaction rates and the Arrhenius equation. As experimental data, temperature dependence of the kinematic viscosity and density of Fe73.5Cu1Mo3Si13.5B9 melt was used. At a temperature of 1600 K, after the melt is overheated above the critical temperature Tk = 1770 K, the nanoparticles size decreases from 0.92 to 0.47 nm, and the diffusion coefficient increases from 2.4·10-10 to 4.5·10-10 m2·s-1.

EXPERIMENTAL TRACKING OF UNSTABLE ORBITS IN DRIVEN DIODE RESONATOR BY WEAK COUPLING

1996 ◽  
Vol 06 (04) ◽  
pp. 769-774 ◽  
Author(s):  
JONG CHEOL SHIN ◽  
SOOK-IL KWUN ◽  
YOUNGTAE KIM
Keyword(s):  
Feedback Control ◽  
Weak Coupling ◽  
Control Parameter ◽  
Chaotic Regime ◽  
Coupling Method ◽  
Generic Properties ◽  
Wide Range ◽  
Resonator System ◽  
Weak Coupling Method

The weak coupling method is demonstrated to stabilize and track the unstable orbits in the diode resonator system. Continuous tracking of the unstable orbits could be achieved over a wide range from the periodic down to the deep chaotic regime as the control parameter is varied continuously without changing the feedback control parameter. During the tracking of unstable orbits, hysteresis as well as switching of the attractors are observed and these are supposed to be the generic properties of continuous tracking.

CRITICAL TEMPERATURE, ISOTOPE EFFECT AND SUPERCONDUCTING GAP IN THE MxLa2−xCuO4 AND M2RCu3O7−δ-TYPE SUPERCONDUCTORS

1988 ◽  
Vol 02 (06) ◽  
pp. 1415-1429 ◽  
Author(s):  
F. H. LIU ◽  
MARIAN APOSTOL
Keyword(s):  
Experimental Data ◽  
High Temperature ◽  
Critical Temperature ◽  
Isotope Effect ◽  
Fair Agreement ◽  
Superconducting Gap ◽  
Mechanism Of Superconductivity

The effect of the oxygen-displacive modes in the M x La 2−x CuO 4 and M 2 RCu 3 O 7−δ-type superconductors is discussed with regard to its possible relevance for a high-temperature mechanism of superconductivity. Critical temperature, isotope effect and superconducting gap are estimated in fair agreement with the experimental data.

Contribution to the Theory of Weak Coupling Superconductors

1971 ◽  
Vol 49 (6) ◽  
pp. 724-746 ◽  
Author(s):  
C. R. Leavens ◽  
J. P. Carbotte
Keyword(s):  
Critical Temperature ◽  
Isotope Effect ◽  
Normal State ◽  
Weak Coupling ◽  
Analytic Solution ◽  
Numerical Solutions ◽  
Approximate Analytic Solution ◽  
Zero Temperature ◽  
Eliashberg Equations ◽  
Normal State Properties

We have managed to simplify the Eliashberg equations for the case of weak coupling superconductors. Further, an explicit approximate analytic solution of the simplified equations has been obtained for the zero temperature gap edge. An expression for the critical temperature is also given. It is found to be of the BCS form and allows the BCS parameter N(0)V to be identified with a simple function of the normal state properties. The validity of our simplified integral equations and of our analytic solution is established by comparison with numerical solutions of the complete Eliashberg equations. The equations are used to discuss the effect of pressure on the gap, the isotope effect, as well as other properties.

A weak coupling method between the dynamics code HOST and the 3D unsteady Euler code WAVES

2001 ◽  
Vol 5 (6) ◽  
pp. 397-408 ◽  
Author(s):  
Gaëlle Servera ◽  
Philippe Beaumier ◽  
Michel Costes
Keyword(s):  
Weak Coupling ◽  
Coupling Method ◽  
Weak Coupling Method
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