Fulde–Ferrell–Larkin–Ovchinnikov states in quasi-two-dimensional d+s-wave superconductors: Enhancement of the upper critical field

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.

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

International Journal of Modern Physics B ◽

10.1142/s0217979203015887 ◽

2003 ◽

Vol 17 (16) ◽

pp. 3001-3020 ◽

Cited By ~ 2

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.

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Upper Critical Field in Electron-Doped Superconductor with Nonstoichiometric Disorder near Antiferromagnetic-Superconducting Phase Boundary

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.215.77 ◽

2014 ◽

Vol 215 ◽

pp. 77-82 ◽

Cited By ~ 5

Author(s):

Tatiana B. Charikova ◽

Nina G. Shelushinina ◽

German I. Harus ◽

Denis S. Petukhov ◽

Andrei A. Ivanov

Keyword(s):

Phase Boundary ◽

Critical Field ◽

Upper Critical Field ◽

Superconducting Phase ◽

Spin Fluctuations ◽

S Wave ◽

Optimal Doping ◽

Resistivity Method ◽

Upward Curvature ◽

Disorder Parameter

Using the resistivity method it was found that temperature dependence of the upper critical field for underdoped Nd1.86Ce0.14CuO4+δ have an anomalous upward curvature of Hc2(T) dependence and can be consistently explained by the two-band/two-gap model of a dirty superconductor. Near antiferromagnetic-superconducting phase boundary the critical temperature remains constant with the change of the disorder parameter and the slope of Bc2 increases with increasing of the disorder parameter. This behavior is completely different from dependencies for pure superconducting phase at optimal doping region. This difference may indicate the change of the type of the paring: from the predominance of the anisotropic s-wave component (may be due to unstable competition between antiferromagnetic (AF) and superconducting (SC) regions) in underdoped (x=0.14) region to the prevalence of d-wave part in optimal doped regions (x=0.15) because of residual spin fluctuations.

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The Temperature of Berezinsky – Kosterlitz – Thouless Transition in Two-Dimensional Superconductor in an External Field

Siberian Journal of Physics ◽

10.54362/1818-7919-2014-9-3-75-80 ◽

2014 ◽

Vol 9 (3) ◽

pp. 75-80

Author(s):

Aleksandr Krinitsyn ◽

Iliya Tikhomirov ◽

Klimentiy Yugay

Keyword(s):

Magnetic Field ◽

Monte Carlo ◽

External Magnetic Field ◽

External Field ◽

Critical Field ◽

Applied Magnetic Field ◽

Coherence Length ◽

Upper Critical Field ◽

Two Dimensional ◽

Calculated Temperature

The Method of Monte-Carlo calculated temperature of Berezinsky – Kosterlitz – Thouless transition in twodimensional superconductor 2nd type in the presence of an external magnetic field. It is shown that near the upper critical field filling cells with a size of ξ × ξ relation, where ξ – coherence length at a given temperature, corresponds to half. It is also shown that ТBKT decreases with increasing interaction between the vortices and antivortices and increase of the external applied magnetic field

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Ginzburg-Landau equation and the upper critical field in anisotropic (d+s)-wave superconductivity

Physical Review B ◽

10.1103/physrevb.55.11730 ◽

1997 ◽

Vol 55 (17) ◽

pp. 11730-11734 ◽

Cited By ~ 17

Author(s):

K. Maki ◽

M. T. Beal-Monod

Keyword(s):

Critical Field ◽

Landau Equation ◽

Upper Critical Field ◽

S Wave ◽

Ginzburg Landau ◽

Ginzburg Landau Equation

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RESISTIVE UPPER CRITICAL FIELD OF SUPERCONDUCTING SPIN-LADDER Sr14-xCaxCu24O41

International Journal of Modern Physics B ◽

10.1142/s0217979200004131 ◽

2000 ◽

Vol 14 (29n31) ◽

pp. 3617-3622 ◽

Cited By ~ 6

Author(s):

T. NAKANISHI ◽

N. MOTOYAMA ◽

H. MITAMURA ◽

N. TAKESHITA ◽

H. TAKAHASHI ◽

...

Keyword(s):

High Pressure ◽

Critical Field ◽

Pressure Range ◽

Upper Critical Field ◽

Anomalous Behavior ◽

Spin Ladder ◽

Two Dimensional ◽

High Pressure Cell ◽

Upward Curvature ◽

Superconducting Oxides

We report the resistive upper critical field Hc2(T) of the hole-doped two-leg ladder Sr 14-x Ca x Cu 24 O 41(x=12) single crystal, which becomes superconducting with Tc~5 K in a pressure range above ~3.0 GPa . Using a newly developed compact high-pressure cell, the magneto-transport measurements have been performed at temperatures down to ~140 mK under high pressure above 3.5 GPa. It is found that Hc2 (perpendicular to the ladder Cu 2 O 3 plane) increases anomalously as the temperature is decreased having an upward curvature and shows no saturation down to T/T c ~ 0.03. Also, its temperature dependence is found to resemble that of the high-Tc superconducting oxide Tl 2 Ba 2 CuO 6. This fact suggests that the anomalous behavior of Hc2 has a common origin between the ladders and the two-dimensional high-Tc superconducting oxides.

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