Temperature dependence of zero-bias conductance peak in Bi2Sr2CaCu2O8+δ-SiO-Ag planar tunnel junctions

Abstract We present the temperature dependence of tunneling spectra of as-grown Bi 2 Sr 2 CaCu 2 O 8+ δ single crystals. An enhancement of the zero-bias conductance peak (ZBCP) was observed for the ab -plane tunnel junctions. The ZBCP has appeared below the bulk superconducting critical temperature T c . This experimental result suggests that the ZBCP obviously arises by way of the superconducting gap and not the pseudogap. This result is consistent with recent studies of the Andreev bound states model for d -wave superconductors.