Nonlinear I-V, High Flux-Flow Velocity Instability and Evidence for Quantum Fluctuations in BSCCO Superconducting Films

摘要

The large flux-flow velocity behavior of the high temperature superconductorBSCCO in the mixed state is studied by measurement of the current-voltagecharacteristic as a function of temperature and magnetic field direction. Wefind strong evidence for vortex-antivortex pairs that are excited by quantumfluctuations and contribute to the dissipation when dissociated by a largecurrent.