ROLE OF HYBRIDIZATION IN THE SUPERCONDUCTING PROPERTIES OF AN EXTENDED d–p HUBBARD MODEL

2004 ◽  
Vol 18 (02) ◽  
pp. 241-252 ◽  
Author(s):  
E. J. CALEGARI ◽  
S. G. MAGALHÃES ◽  
A. A. GOMES
Keyword(s):  
Hubbard Model ◽  
Order Parameter ◽  
Superconducting Order Parameter ◽  
Superconducting Properties

In this work the variational Roth's approach previously developed by the present authors to describe cuprate systems is extended to include the superconducting properties. We extend the Beenen and Edwards approach by including the d–p hybridization. The role of the d–p hybridization in modifying the values of superconducting order parameter is then studied in terms of the adopted values of the parameters defining the Hamiltonian of the system.

scholarly journals Зависимость критической температуры цилиндрических сверхпроводников от граничных условий

2020 ◽  
Vol 62 (10) ◽  
pp. 1594
Author(s):  
А.Н. Лыков
Keyword(s):  
Boundary Conditions ◽  
Coherence Length ◽  
Order Parameter ◽  
Landau Theory ◽  
Small Diameter ◽  
Superconducting Order Parameter ◽  
Superconducting Properties ◽  
Ginzburg Landau

The paper presents the results of a study of the properties of long cylindrical superconductors with a diameter of the order of coherence length ξ, performed in the framework of the Ginzburg-Landau theory (GL). Boundary conditions of general form are used for solution of the GL equa-tion for superconducting order parameter. Using such boundary conditions allows us to take into account the influence of the cylinder boundary on its superconducting properties. This ap-proach is important for small-diameter cylinders, whose properties significantly depend on the properties of their boundaries.

scholarly journals Variation of the extended s-wave superconducting order parameter: From s-wave to g-wave

2015 ◽  
Vol 29 (27) ◽  
pp. 1550163
Author(s):  
H. Chung ◽  
N. Kim ◽  
H. Kim
Keyword(s):  
Fermi Surface ◽  
Density Of States ◽  
Power Law ◽  
Order Parameter ◽  
Superconducting Order Parameter ◽  
Text Line ◽  
Superconducting Properties ◽  
Detailed Structure ◽  
S Wave ◽  
Model Order

We investigate evolution of properties of an extended [Formula: see text]-wave superconductor, when the order parameter varies from an [Formula: see text]-wave to a [Formula: see text]-wave continuously, by using a model order parameter [Formula: see text]. The evolution of the gap amplitude, the density of states and the specific heat are mainly focused on. For [Formula: see text], due to the existence of a finite sized gap, the characteristic behaviors more or less follow those of the [Formula: see text]-wave. Sudden changes in the characteristic behaviors come out for [Formula: see text], due to appearances of nodes. For [Formula: see text], point nodes in the order parameter on the Fermi surface appear, while for [Formula: see text], line nodes appear. Although they are different kinds of nodes which would usually induce different power-law dependencies in superconducting properties, interestingly enough, they give rise to the same characteristic behavior. The detailed structure of the point nodes for [Formula: see text] is investigated, and it is explained why they lead to the same dependence as the line nodes.

scholarly journals Triggering avalanches by transverse perturbations in a rotating drum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vicente Salinas ◽  
Cristóbal Quiñinao ◽  
Sebastián González ◽  
Gustavo Castillo
Keyword(s):  
Hopf Bifurcation ◽  
Theoretical Model ◽  
Order Parameter ◽  
Small Scale ◽  
Rotating Drum ◽  
Governing Parameter ◽  
Stick Slip ◽  
Slip Regime ◽  
Axis Of Rotation

AbstractWe study the role of small-scale perturbations in the onset of avalanches in a rotating drum in the stick-slip regime. By vibrating the system along the axis of rotation with an amplitude orders of magnitude smaller than the particles’ diameter, we found that the order parameter that properly describes the system is the kinetic energy. We also show that, for high enough frequencies, the onset of the avalanche is determined by the amplitude of the oscillation, contrary to previous studies that showed that either acceleration or velocity was the governing parameter. Finally, we present a theoretical model that explains the transition between the continuous and discrete avalanche regimes as a supercritical Hopf bifurcation.

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