Thermal effects and diamagnetic response of a current-carrying YBCO film

The temperature dependence of the dissipative part of the response to an ac magnetic field has been studied for an YBCO high-temperature superconductor film carrying a transport current. The response is found to exhibit a thermal hysteresis, whose magnitude depends on the transport current. The hysteresis is assigned to the current-carrying superconductor having two stable equilibrium states within a certain thermostat temperature interval. The existence of these states governed by specific features of the release and removal of heat.