Published May 1, 1992 | Version v1
Journal article

Electron tunneling spectroscopy of single-crystal Bi2Sr2CaCu2O8

  • 1. Polytechnic University, Brooklyn, New York 11201 (United States)

Description

The T-dependent conductance G(V,T) of evaporated Pb junctions on cleaved ab planes of Bi2Sr2CaCu2O8 (2:2:1:2) crystals is presented. Strong superconducting Gs(V,T) structures imply a large gap, approximately Δ0(0)=26 meV, or 2Δ0(0)/kBTc=6.7. An analysis of G(V,T) near Tc, assuming a lifetime-broadened BCS Ns(E), reveals a broadening Γ(T) such that Δ(Tc)∼Γ(Tc)∼2kBTc. The fitted Δ(Tc), unlike typical BCS values, is ∼0.8Δ(0). $G(V,T>T sub c )--- has a minimum at V=0, suggestive of known c-direction localization in 2:2:1:2 compounds. G(V,T) also reveals the expected fluctuation superconductivity above Tc. 4.2-K scanning-tunneling-microscope (STM) spectra are mentioned in comparison. A larger gap, about 40 meV, and dip at 80 meV, found in the STM G(V) are tentatively attributed to CuO2 planes

Additional details

Publishing Information

Journal Title
Physical Review. B, Condensed Matter
Journal Volume
45
Journal Issue
18
Journal Page Range
p. 10622-10632.
ISSN
0163-1829
CODEN
PRBMDO