Strong thermal fluctuations in cuprate superconductors in magnetic field above Tc

Abstract

Recent measurements of fluctuation diamagnetism in high temperature superconductors show distinct features above and below Tc, which can not be explained by simple gaussian fluctuation theory. Self consistent calculation of magnetization in layered high temperature superconductors, based on the Ginzburg-Landau-Lawrence-Doniach model and including all Landau levels is presented. The results agree well with the experimental data in wide region around Tc, including both the vortex liquid below Tc and the normal state above Tc. The gaussian fluctuation theory significantly over estimates the diamagnetism for strong fluctuations. It is demonstrated that the intersection point of magnetization curves appears in the region where the lowest Landau level contribution dominates.

5 pages, 4 figures

References in corpus (10)

• A Common Thread: the pairing interaction for the unconventional superconductors
• Decrease of upper critical field with underdoping in cuprate superconductors
• Giant Nernst Effect due to Fluctuating Cooper Pairs in Superconductors
• Diamagnetism around the Meissner transition in a homogeneous cuprate single crystal
• Fluctuation diamagnetism in high temperature superconductors
• Field-induced magnetic order in La$sub2-x$Sr$subx$CuO$sub4$ (x = 0.10, 0.115, 0.13) studied by in-plane thermal conductivity measurements
• Comment on 'Diamagnetism and Cooper pairing above Tc in cuprates'
• Phase fluctuations versus Gaussian fluctuations in optimally-doped YBa${}_2$Cu${}_3$O${}_7$
• Study of diamagnetic fluctuations in YBa_2Cu_3O_{7-x} and Bi_2Sr_2CaCu_2O_{8+x}: Possible observation of phase correlations persisting above T_c
• Magnetic phase diagram of the layered superconductor Bi{2+x}Sr{2-x}CuO{6+δ} (Bi2201) with Tc~7 K

Cited by in corpus (8)

• Cuprate diamagnetism in the presence of a pseudogap: Beyond the standard fluctuation formalism
• Covariant gaussian approximation in Ginzburg - Landau model
• Study of Nb${}_{0.18}$Re${}_{0.82}$ non-centrosymmetric superconductor in the normal and superconducting states
• The conductivity and the magnetization around Tc in optimally-doped YBa${}_2$Cu${}_3$O${}_{7-\delta }$ revisited: quantitative analysis in terms of fluctuating superconducting pairs
• Fluctuation Diamagnetism in Two-Band Superconductors
• A quantitative description of Nernst effect in high-temperature superconductors
• Enhanced superconducting-fluctuation effects on thermodynamic properties in BCS-BEC-crossover regime
• Concurrent intersection point of magnetization and magneto-conductivity curves in strongly fluctuating superconductors