TRANSPORT PHENOMENA IN THE MIXED STATE AND FLUCTUATION REGIME IN (Bi1.6Pb0.4)Sr2Ca1-xHox(Cu1-yZny)2O8+d

2001 ◽  
Vol 15 (21) ◽  
pp. 929-934
Author(s):  
G. ILONCA ◽  
A. V. POP ◽  
R. STIUFIUC ◽  
G. STIUFIUC ◽  
C. LUNG ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mixed State ◽  
Landau Theory ◽  
Hole Concentration ◽  
Transport Coefficients ◽  
Time Dependent ◽  
Ginzburg Landau ◽  
Metallic Behavior ◽  
Fluctuation Effects ◽  
Longitudinal Resistivity

Measurements of the magnetoresistivity, Seebeck, Nernst and Hall coefficients in Bi:2212 superconductors doped with Ho and Zn are reported. The critical temperature and the transport coefficients depend strongly on the Ho and Zn contents. The tails of the transport coefficients versus temperature curves are caused by fluctuation effects, which increase with increasing magnetic field. An anomalous suppression of superconductivity at x = 0.25–0.35 and y = 0.025–0.032 was also found when the hole concentration per Cu is P H = 1/8 and the transport properties exhibit metallic behavior. It was found that dB c2 /dT = -2.4 ± 0.2 T/K , corresponding to a Ginzburg–Landau coherence length ξ = 15 Å. The Hall resistivity ρxy scaling with the longitudinal resistivity ρxx as [Formula: see text] with α ≈ 1.8 is in agreement with the theory of Vinokur et al. The experimental data in the mixed state are in agreement with the prediction of the time-dependent Ginzburg–Landau theory.

Dynamics of vortex–antivortex creation and annihilation in current-driven mesoscopic superconducting squares

2015 ◽  
Vol 29 (35n36) ◽  
pp. 1550247
Author(s):  
Xiao-Meng Liang ◽  
Guo-Qiao Zha
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Landau Theory ◽  
Symmetric Case ◽  
Time Dependent ◽  
Dynamical Process ◽  
Applied Bias ◽  
Ginzburg Landau ◽  
Dc Drive ◽  
Vortex Velocity

In this paper, based on the time-dependent Ginzburg–Landau theory, we study the dynamics of vortex–antivortex (V–Av) pairs in a mesoscopic superconducting square with a small hole under applied bias currents. For the sample with a centered hole, a V–Av pair can nucleate at the hole edges and moves in opposite directions perpendicular to applied constant DC drive. The influence of the external magnetic field on the (anti)vortex velocity and the lifetime of V–Av pairs is mainly investigated. Different modes in the dynamical process of the V–Av collision and annihilation are identified. Moreover, in the case when the hole is displaced from the center of the square, the V–Av dynamics behaves quite differently from the symmetric case due to the shift of the V–Av creation point.

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.

scholarly journals Solution Theory of Ginzburg-Landau Theory on BCS-BEC Crossover

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shuhong Chen ◽  
Zhong Tan
Keyword(s):  
Global Existence ◽  
Strong Solution ◽  
Sobolev Spaces ◽  
Landau Theory ◽  
Strong Solutions ◽  
Time Dependent ◽  
Solution Theory ◽  
Ginzburg Landau ◽  
Spatial Dimensions

We establish strong solution theory of time-dependent Ginzburg-Landau (TDGL) systems on BCS-BEC crossover. By the properties of Besov, Sobolev spaces, and Fourier functions and the method of bootstrapping argument, we deduce that the global existence of strong solutions to time-dependent Ginzburg-Landau systems on BCS-BEC crossover in various spatial dimensions.

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.

scholarly journals Existence and uniform boundedness of strong solutions of the time-dependent Ginzburg-Landau equations of superconductivity

2005 ◽  
Vol 2005 (8) ◽  
pp. 863-887
Author(s):  
Fouzi Zaouch
Keyword(s):  
Magnetic Field ◽  
Existence And Uniqueness ◽  
Uniform Boundedness ◽  
Strong Solutions ◽  
Time Dependent ◽  
Dynamical Process ◽  
Ginzburg Landau ◽  
Ginzburg Landau Equations ◽  
Uniformly Bounded ◽  
Weak And Strong Solutions

The time-dependent Ginzburg-Landau equations of superconductivity with a time-dependent magnetic fieldHare discussed. We prove existence and uniqueness of weak and strong solutions withH1-initial data. The result is obtained under the “φ=−ω(∇⋅A)” gauge withω>0. These solutions generate a dynamical process and are uniformly bounded in time.

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