We report electron tunneling evidence for a pseudogap in the normal state excitation spectrum of as-grown Bi2Sr2CaCu2O8+δ (Bi2212) single crystals. The normalized conductance curves show that the gap structure does not disappear at Tc but at much higher temperature T*; the lower bound of T* is within 110 K to 150 K for the investigated three junctions. The result gives a support for the existence of paired carriers in the normal state of cuprate superconductor Bi2212.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering