2007/03/07 by Zhao, S. P., Zhu, X. B., Wei, Y. F.
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · doi:10.48550/arxiv.cond-mat/0703177
We report tunneling spectra of near optimally doped Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions with area of 0.09 μm2, which avoid some fundamental difficulties in the previous tunneling experiments and allow a stable temperature-dependent measurement. A d-wave Eliashberg analysis shows that the spectrum at 4.2 K can be well fitted by considering electron couplings to a bosonic magnetic resonance mode and a broad high-energy continuum. Above Tc, the spectra show a clear pseudogap that persists up to 230 K, and a crossover can be seen indicating two different pseudogap phases existing above Tc. The intrinsic electron tunneling nature is discussed in the analysis.