Ginzburg–Landau theory for two-band s-wave superconductors: application to non-magnetic borocarbides LuNi2B2C, YNi2B2C and magnesium diboride MgB2

2003 ◽  
Vol 397 (3-4) ◽  
pp. 99-111 ◽  
Author(s):  
I.N. Askerzade
Keyword(s):  
Magnesium Diboride ◽  
Landau Theory ◽  
S Wave ◽  
Ginzburg Landau

Mean-field analysis on the magnetic properties of non-centrosymmetric superconductor LaNiC2

2018 ◽  
Vol 96 (2) ◽  
pp. 189-193
Author(s):  
Jia-Li Zhang
Keyword(s):  
Critical Field ◽  
Landau Theory ◽  
Theoretical Calculations ◽  
Mean Field ◽  
Upper Critical Field ◽  
Field Analysis ◽  
S Wave ◽  
Wave State ◽  
Ginzburg Landau ◽  
Upward Curvature

Based on two-band isotropic Ginzburg–Landau theory, we study the temperature dependence of upper critical field and London penetration depth for non-centrosymmetric superconductor LaNiC2. All the theoretical calculations fit the experimental data very well, especially the upward curvature of upper critical field near the critical temperature. Our results thus indicate that the two-gap scenario is better to account for the superconductivity of LaNiC2, and the Cooper pairs of this superconductor are in the conventional s-wave state.

TEMPERATURE DEPENDENCE OF THE CRITICAL CURRENT DENSITY OF SUPERCONDUCTORS IN TWO-BAND GINZBURG–LANDAU THEORY: APPLICATION TO MgB2

2004 ◽  
Vol 18 (13) ◽  
pp. 1931-1936 ◽  
Author(s):  
I. N. ASKERZADE
Keyword(s):  
Critical Current Density ◽  
Temperature Dependence ◽  
Critical Current ◽  
Current Density ◽  
Magnesium Diboride ◽  
Landau Theory ◽  
Ginzburg Landau ◽  
Theory Application ◽  
Gl Theory ◽  
Good Agreement

Temperature dependence of the critical current density j c (T) for the superconducting magnesium diboride MgB 2 is studied in the vicinity of T c by using a two-band Ginzburg–Landau (G–L) theory. The result is in good agreement with experimental data for a bulk MgB 2. Comparision of obtained results with single-band GL theory are presented.

Ginzburg–Landau Theory for Two-Band Isotropic s-Wave Superconductors

2003 ◽  
Vol 17 (16) ◽  
pp. 3001-3020 ◽  
Author(s):  
I. N. Askerzade
Keyword(s):  
Magnetic Field ◽  
Critical Field ◽  
Landau Theory ◽  
Upper Critical Field ◽  
Single Band ◽  
S Wave ◽  
Ginzburg Landau ◽  
Surface Magnetic Field ◽  
Specific Heat Jump ◽  
Gl Theory

Temperature dependence of the upper critical field Hc2(T), lower critical field Hc1(T) and thermodynamic magnetic field Hcm(T) are studied in the vicinity of Tc using a two-band Ginzburg–Landau (GL) theory. The results are shown to be in a good agreement with experimental data for the superconducting magnesium diboride (MgB2) and non-magnetic borocarbides LuNi 2 B 2 C ( YNi 2 B 2 C ). In addition, two-band GL theory was applied for the calculation of specific heat jump, which is smaller than in single-band GL theory. Peculiarities of Little–Parks effect in two-band GL theory are studied also. It is shown that the quantization of the magnetic flux and the relation between surface magnetic field Hc3(T) and upper critical field Hc2(T) are the same as in single band GL theory.

s-Wave holographic superconductor in different ensembles and its thermodynamic consistency

2017 ◽  
Vol 26 (04) ◽  
pp. 1750027
Author(s):  
Lei Yin ◽  
Defu Hou
Keyword(s):  
Order Parameter ◽  
Helmholtz Free Energy ◽  
Canonical Ensemble ◽  
Landau Theory ◽  
Equation Of Motion ◽  
Superconducting Phase ◽  
S Wave ◽  
Holographic Superconductor ◽  
Thermodynamic Relation ◽  
Ginzburg Landau

In this paper, we analytically study the consistency between the Ginzburg–Landau theory of the holographic superconductor in different ensembles and the fundamental thermodynamic relation, we derive the equation of motion of the scalar field which depicts the superconducting phase in canonical ensemble (CE) and a consistent formula to connect the holographic order-parameter to the Ginzburg–Landau coefficients in different thermodynamic ensembles, and we also study the spatially nonuniform Helmholtz free energy.

scholarly journals A GENERALIZATION OF THE GINZBURG–LANDAU THEORY TO p-WAVE SUPERCONDUCTORS

2008 ◽  
Vol 22 (18) ◽  
pp. 1709-1716 ◽  
Author(s):  
E. DI GREZIA ◽  
S. ESPOSITO ◽  
G. SALESI
Keyword(s):  
Present Model ◽  
Landau Theory ◽  
Magnetic Behavior ◽  
P Wave ◽  
Cooper Pairs ◽  
S Wave ◽  
Ginzburg Landau ◽  
Original Medium ◽  
Mean Fields ◽  
Spin Triplet

We succeed in building up a straightforward theoretical model for spin-triplet p-wave superconductors, by introducing a second-order parameter and a nonlinear interaction between the two mean fields in the Ginzburg–Landau theory. Such interaction breaks the isotropy of the original medium and allows pairs of electrons to arrange into S = 1 Cooper pairs. The present model predicts a thermodynamical and magnetic behavior analogous to that observed in conventional s-wave superconductors.

Singular and Nonsingular Vortex Structures in High-Temperature Superconductors

2003 ◽  
Vol 17 (10n12) ◽  
pp. 621-626
Author(s):  
A. S. Bystrov ◽  
A. S. Mel'Nikov ◽  
D. A. Ryzhov ◽  
I. M. Nefedov ◽  
I. A. Shereshevskii ◽  
...  
Keyword(s):  
High Temperature ◽  
Vortex Core ◽  
Landau Theory ◽  
High Temperature Superconductors ◽  
Flux Line ◽  
Vortex Structures ◽  
Time Dependent ◽  
S Wave ◽  
Ginzburg Landau ◽  
Flux Lines

In this paper we focus on the comparison of the equilibrium and transport properties of singular and nonsingular vortex structures in high-temperature compounds. Using the time-dependent Ginzburg–Landau theory we study the dynamics of vortex structures in superconductors with (d+s)-wave pairing. We calculate the angular dependent correction to the viscosity tensor of a singular flux line, which appears due to the admixture of subdominant s-wave order parameter component in the vortex core. The second order phase transition between singular and nonsingular vortices in high-temperature superconductors was simulated within the time-dependent Ginzburg-Landau equations. The semiclassical analysis of the positions of gap nodes in the vortex core is performed both for singular and nonsingular flux lines.

scholarly journals Possible Alterations of Local Gravitational Field Inside a Superconductor

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 193 ◽  
Author(s):  
Giovanni Alberto Ummarino ◽  
Antonio Gallerati
Keyword(s):  
Gravitational Field ◽  
Landau Theory ◽  
Time Dependent ◽  
Qualitative Comparison ◽  
Ginzburg Landau ◽  
High Tc ◽  
Gravitational Fields ◽  
Favorable Conditions

We calculate the possible interaction between a superconductor and the static Earth’s gravitational fields, making use of the gravito-Maxwell formalism combined with the time-dependent Ginzburg–Landau theory. We try to estimate which are the most favorable conditions to enhance the effect, optimizing the superconductor parameters characterizing the chosen sample. We also give a qualitative comparison of the behavior of high–Tc and classical low–Tc superconductors with respect to the gravity/superfluid interplay.

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