Observation of supercurrent distribution in YBCO thin film devices by photoexcited THz radiation

An imaging supercurrent distribution technique in high-temperature superconducting thin film devices is presented. The methodology, which uses photoexcited THz radiation, obtains the images by scanning focused femtosecond laser pulses on the superconducting film devices while in the process of detecting the THz radiation. The Bean critical state model is used to interpret the distribution of the obtained transport and persisting currents.