Evidence for pseudogap and phase-coherence gap separation by Andreev reflection experiments in Au/La2-xSrxCuO4 point-contact junctions

We present new Au/La2-xSrxCuO4 (LSCO) point-contact conductance measures as a function of voltage and temperature in samples with 0.08 less than or eq ual to x less than or equal to 0.2. Andreev reflection features disappear a t about the bulk T-c, giving no evidence of gap for T > T-c. The fit of the normalized conductance at any T < T-c supports a (s+d)-wave symmetry of th e gap, whose dominant low-T s component follows the T-c(x) curve in contras t with recent angle-resolved photoemission spectroscopy and quasiparticle t unneling data. These results prove the separation between pseudogap and pha se-coherence superconducting gap in LSCO at x less than or similar to 0.2.