Low-temperature formation of thermal and electrodynamic states in Bi₂Sr₂CaCu₂O₈

Abstract

The formation of thermal and electrodynamic states in Bi₂Sr₂CaCu₂O₈ under the condition of current input is studied. The analysis is carried out for partial and complete current penetration under the assumption that the superconductor is cooled down to liquid helium temperature at the zero time. When the current input is continuous, the temperature dependence of the Bi₂Sr₂CaCu₂O₈ specific heat influences the form of the I-V and I-T characteristics of the superconductor. This effect is observed at high electric fields when both stable and unstable states form. As a result, the nonstationary I-V characteristic of Bi₂Sr₂CaCu₂O₈ has the only branch the slope of which is positive and decreases with increasing temperature. Therefore, the higher the rate of current input, the more pronounced the decrease in the slope. It is concluded that one cannot find the current above which instability develops from the Bi₂Sr₂CaCu₂O₈ I-V characteristic if the current input is continuous.