Critical temperature and the Ginzburg-Landau theory of layered high-temperature superconductors

1989 ◽  
Vol 33 (3) ◽  
pp. 351-355 ◽  
Author(s):  
T. Schneider
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Landau Theory ◽  
High Temperature Superconductors ◽  
Ginzburg Landau

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 Torque magnetometry on single-crystal high-temperature superconductors near the critical temperature: A scaling approach

2000 ◽  
Vol 62 (1) ◽  
pp. 631-639 ◽  
Author(s):  
J. Hofer ◽  
T. Schneider ◽  
J. M. Singer ◽  
M. Willemin ◽  
H. Keller ◽  
...  
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Single Crystal ◽  
High Temperature Superconductors ◽  
Torque Magnetometry

scholarly journals Superconducting Hydrides Under Pressure

2020 ◽  
Vol 11 (1) ◽  
pp. 57-76 ◽  
Author(s):  
Chris J. Pickard ◽  
Ion Errea ◽  
Mikhail I. Eremets
Keyword(s):  
Hydrogen Sulfide ◽  
High Temperature ◽  
Critical Temperature ◽  
First Principles ◽  
High Temperature Superconductors ◽  
Microscopic Structure

The measurement of superconductivity at above 200 K in compressed samples of hydrogen sulfide and in lanthanum hydride at 250 K is reinvigorating the search for conventional high temperature superconductors. At the same time, it exposes a fascinating interplay between theory, computation, and experiment. Conventional superconductivity is well understood, and theoretical tools are available for accurate predictions of the superconducting critical temperature. These predictions depend on knowing the microscopic structure of the material under consideration, which can now be provided by computational first-principles structure predictions. The experiments at the megabar pressures required are extremely challenging, but, for some groups at least, permit the experimental exploration of materials space. We discuss the prospects for the search for new superconductors, ideally at lower pressures.

scholarly journals THE 3d-TO-4s-BY-2p HIGHWAY TO SUPERCONDUCTIVITY IN CUPRATES

2002 ◽  
Vol 16 (30) ◽  
pp. 4577-4585 ◽  
Author(s):  
TODOR M. MISHONOV ◽  
JOSEPH O. INDEKEU ◽  
EVGENI S. PENEV
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
High Temperature Superconductors ◽  
Electron Exchange ◽  
Theoretical Physics ◽  
Pairing Interaction ◽  
Electron Pairing

High-temperature superconductors are nowadays found in great variety and hold technological promise. It is still an unsolved mystery that the critical temperature T c of the basic cuprates is so high. The answer might well be hidden in a conventional corner of theoretical physics, overlooked in the recent hunt for exotic explanations of new effects in these materials. A forgotten intra-atomic s–d two-electron exchange in the Cu atom is found to provide a strong (~ eV) electron pairing interaction. A Bardeen–Cooper–Schrieffer approach can explain the main experimental observations and predict the correct dx2-y2 symmetry of the gap.

Fluorine Substitution in High Temperature Superconductors

1999 ◽  
Vol 13 (09n10) ◽  
pp. 973-978 ◽  
Author(s):  
E. Bellingeri ◽  
G. Grasso ◽  
R. Gladyshevskii ◽  
E. Giannini ◽  
F. Marti ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Critical Temperature ◽  
Low Temperature ◽  
High Temperature Superconductors ◽  
Irreversibility Field ◽  
Fluorine Substitution ◽  
Superconducting Phases

Fluorine substitution in the Bi(2223), Bi(2212) and Tl(1223) superconducting phases was studied. We obtained superconducting structures, never observed before, of the Bi-based superconductors by a low temperature (200-400 °C) fluorination process. Fluorine substitutes completely the oxygen sites in the Bi layers and additional F atoms are inserted in the structure. As a consequence, changes in the arrangements of cation and anions were induced, especially in the Bi and partially in the Sr layer. F-doped Tl(1223) has been prepared in the same way as Bi(2223) and Bi(2212) (low temperature fluorination), but also starting from precursor containing fluorides of different elements. No significant differences in the crystal structure have been observed between the Tl-based samples with F inclusions and without. The critical temperature (116 K) remains unchanged but a significant increase of the irreversibility field at low temperature was found.

Sign in / Sign up

Export Citation Format

Share Document