Point-contact spectroscopy of the high-temperature superconductor BiSrCaCuO

The maximum value of the energy gap $\mathrm{\Delta }\simeq 8meV$ and the ratio $2\delta \mathrm{/}k{T}_c\simeq 2.5$ are determined for a high-temperature superconductor $\mathrm{B}{\mathrm{i}}_2\mathrm{S}{\mathrm{r}}_2\mathrm{C}\mathrm{a}\mathrm{C}{\mathrm{u}}_2{\mathrm{O}}_{8+\mathrm{y}}$ by using point contacts. It was found that the high-temperature superconductor is transformed under the effect of current injection of quasiparticles to a new modified state with a reduced gap, which is stable in a wide range of injection intensity.