Experimental evidence in favor of the fluctuation origin of the transverse-resistance increase near the edge of the superconducting transition in Bi2Sr2CaCu2O8+ delta.

Abstract

The experimentally observed increase of the transversal resistance near the edge of the transition in ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$${\mathrm{CaCu}}_{2}$${\mathrm{O}}_{8+\mathrm{\ensuremath{\delta}}}$ epitaxial film is analyzed on the basis of a recent theoretical proposal on its fluctuation origin [L. Ioffe, A. I. Larkin, A. A. Varlamov, and L. Yu, Phys. Rev. B (to be published). It is shown that the excess resistance in a wide range of temperatures increases logarithmically as the superconducting transition temperature is approached from above, in agreement with the theoretical consideration. These results are also compared with the available data on ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ compounds.