Role of Density of States in the Fluctuation Conductivity of Bi₂Sr₂CaCu₂O₈ and Tl₂Ba₂CaCu₂O₈ Single Crystals

Abstract

The out-of-plane resistivity ρ_c (T, B) of Bi₂Sr₂CaCu₂O₈ and Tl₂Ba₂CaCu₂O₈ single crystals has been measured in weak magnetic fields applied perpendicular to the ab-plane. The measurement show a well pronounced peak at a temperature T_m. The external magnetic field shifts T_m towards lower temperatures and increases the magnitude of the peak. We demonstrate that the ρ_c (T, O) is well described by the fluctuation theory, developed by Dorin et al., in the Gaussian approximation over a wide range of temperature, but in the presence of field, fluctuations are better described in Hartree approximation.

Indexing terms:

• Out-of-plane
• TBCCO
• BSCCO
• Superconductivity

Additional information

Notes on contributors

P Chowdhury

Prasanta Chowdhury was born on 10th May 1971. Presently he is with the Department of Physics, Indian Institute of Technology, Powai, Mumbai. He did his BSc in & MSc from Burdwan University in the year 1992 & 1995 respectively and doing PhD from NT, Bombay. At present he is working in the field of thermodynamical fluctuations in high Tc materials. The main interest is to study intrinsic properties of these grown crystals along the c-axis, which can be compared with the stack of Josephson junctions and the properties of these intrinsic junctions may be utilised to develop digital circuit at low temperature with high accuracy.