Point-contact spectroscopy of superconducting YBaCuO single crystals of tetragonal modification
The point-contact spectra of tetragonal $\rm YBa_2Cu_3O_{7-δ}$ with $T_c=50-60~K$ are studied at various temperatures. The single-electron energy ($2Δ_0/kT_c\simeq 17$) and its temperature dependence are determined. The characteristic energies of quasiparticle excitations interacting with conduction electrons in this high-$T_c$. superconductor are found to correlate with the characteristic phonon energies. The possibility of a pair gap, which increases with temperature, is revealed near the critical temperature.
cond-mat.supr-con↗