We studied the doping dependence of the superconducting gap in La22xSrxCuO4 (LSCO) by means of Andreev reflection measurements in Au/LSCO point-contact junctions. The Andreev reflection features were found to disappear at Tc.A close to the bulk Tc. The fit of the conductance curves with the BTK–Tanaka–Kashiwaya model gives good results if a (s þ d)-wave gap symmetry is used. The low-temperature dominant isotropic gap component Ds follows very well the Tc vs. x curve, while the gap-like features observed by angle-resolved photoemission spectroscopy and tunneling scale with T p. This confirms the different origin of these two energy scales at T<Tc
Doping dependence of the superconductung gap by Andreev reflection in Au/La2 xSrxCuO4 point-contact junctions
FERRETTI, MAURIZIO
2002-01-01
Abstract
We studied the doping dependence of the superconducting gap in La22xSrxCuO4 (LSCO) by means of Andreev reflection measurements in Au/LSCO point-contact junctions. The Andreev reflection features were found to disappear at Tc.A close to the bulk Tc. The fit of the conductance curves with the BTK–Tanaka–Kashiwaya model gives good results if a (s þ d)-wave gap symmetry is used. The low-temperature dominant isotropic gap component Ds follows very well the Tc vs. x curve, while the gap-like features observed by angle-resolved photoemission spectroscopy and tunneling scale with T p. This confirms the different origin of these two energy scales at T
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