Ginzburg–Landau theory of the Abrikosov vortex state near the upper critical field

1982 ◽  
Vol 60 (3) ◽  
pp. 299-303 ◽  
Author(s):  
A. E. Jacobs
Keyword(s):  
Critical Field ◽  
Landau Theory ◽  
Upper Critical Field ◽  
Vortex State ◽  
Quantization Condition ◽  
Abrikosov Vortex ◽  
Ginzburg Landau ◽  
Type Ii Superconductors ◽  
Flux Quantization ◽  
The Magnetic Field

A method which preserves the flux-quantization condition in all orders of perturbation theory is applied to the Ginzburg–Landau theory of type-II superconductors near the upper critical field. Expansions are obtained for the order parameter, the magnetic field, and the free energy; previous results are verified and extended to one higher order in Hc2 – Ha.

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.

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.

DETERMINATIONS OF UPPER CRITICAL FIELDS IN CONTINUOUS GINZBURG–LANDAU MODEL

2004 ◽  
Vol 15 (06) ◽  
pp. 783-807
Author(s):  
L. WANG ◽  
H. S. LIM ◽  
C. K. ONG
Keyword(s):  
Critical Field ◽  
Eigenvalue Problems ◽  
Upper Critical Field ◽  
Critical Fields ◽  
Ginzburg Landau ◽  
Direction Parallel ◽  
Landau Model ◽  
The Magnetic Field ◽  
Good Agreement

Novel procedures to determine the parallel upper critical field Bc2 (one-dimensional, 1D) have been proposed within a continuous Ginzburg–Landau model. Unlike conventional methods, where Bc2 is obtained through the determination of the smallest eigenvalue of an appropriate eigen equation, the square of the magnetic field is treated as eigenvalue problems by two procedures so that the upper critical field can be directly deduced. The two procedures proposed are extended to determine the upper critical field in the c–a crystal plane (two-dimensional, 2D) with an arbitrary angle θ tilted from the c-axis. The calculated Bc2 from the two procedures are consistent with each other in both 1D and 2D cases. Moreover, the values of Bc2 near the direction parallel to the layers obtained in the 2D case well approximate the counterparts in the 1D case. The properties of the calculated Bc2 are in reasonably good agreement with existing theories and experiments. The profiles of the order parameters associated with Bc2 for both 1D and 2D cases are Gaussian-like, further validating the methodology proposed.

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