Evaluation of Supercurrent Distribution by Terahertz Radiation Mapping

摘要

We propose and demonstrate a new visualization method of supercurrent distribution in high-T_c superconducting films by mapping terahertz radiation. Using this method, we observed transport current distribution in YBCO thin films. Supercurrent flows near the edge of a YBCO strip line when the bias current is sufficiently small compared to the critical current. The distribution of the supercurrent expands from the edge to the center of the strip line with increasing the bias current, which is qualitatively consistent with the Bean critical state model.