Gap anisotropy and van Hove singularities in high {Tc} superconductors

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:538197

Bok, J; Bouvier, J ^[1]

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1. ESPCI, Paris (France). Lab. de Physique du Solide

The authors compute the superconducting gap {Delta}{sub {rvec k}} using a simple band structure of the CuO{sub 2} planes in the high Tc materials. They suppose that for materials with doping corresponding to maximum {Tc}, the van Hove singularities lie close to the Fermi level as is confirmed by many photoemission experiments. They use a electron-photon interaction with weak screening, they find a strong gap anisotropy. For Bi 2212, {Delta} is maximum along the 100 and 010 directions with values between 20 and 30 meV and minimum along 110 with values between 0 and 10 meV. They use this anisotropic gap to compute the quasi-particle excitations density of states and the tunneling current-voltage I(V) characteristic for N-I-S and S-I-S junctions. This model agrees remarkably well with recent experiments of tunneling spectroscopy in high {Tc} cuprates.

• OSTI ID: 538197
• Report Number(s): CONF-960163--; ISBN 0-8194-2070-0
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
BAND THEORY
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
ENERGY GAP
HIGH-TC SUPERCONDUCTORS
STRONTIUM OXIDES
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
VAN HOVE-HUGENHOLTZ THEORY