The pseudogap in single crystals from tunneling measurements: A possible evidence for the Cooper pairs above
Université Libre de Bruxelles, Service de Physique des Solides CP233,
Blvd. du Triomphe, B-1050 Brussels, Belgium
Accepted: 21 October 1999
We present electron-tunneling spectroscopy of slightly overdoped (Bi2212) single crystals with –90 K in a temperature range between 14 K and 290 K using a break-junction technique. The pseudogap which has been detected above appears at . The analysis of the spectra shows that there is a contribution to the pseudogap above , which disappears approximately at 110–115 K. We associate this contribution with the presence of incoherent Cooper pairs.
PACS: 74.50.+r – Proximity effects, weak links, tunneling phenomena, and Josephson effects / 74.25.-q – General properties; correlations between physical properties in normal and superconducting states / 74.72.Hs – Bi-based cuprates
© EDP Sciences, 2000