论文标题
扫描门显微镜显微镜成像，对平面Josephson Junction中的超潮流分布的理论成像
Theory of scanning gate microscopy imaging of the supercurrent distribution in a planar Josephson junction
论文作者
论文摘要
从理论上讲，我们通过扫描门显微镜技术在存在垂直磁场的情况下，在平面超导体非正常渗透器连接中研究超电流分布的映射。我们发现，如果扫描探针尖端引起的临界电流的变化可以绘制出约瑟夫森涡流中对齐的反传播的超电流的分布，如果连接中的通量接近弗劳恩霍夫模式的最大值。取而代之的是，当磁场将连接处驱动到Fraunhofer图案中的最小值时，超导相适应，而尖端始终会增加超电流。垂直磁场导致约瑟夫森涡流的形成，其高度透明连接的延伸取决于当前的循环方向。我们表明，这导致连接处的不对称超电流分布，并且可以通过扫描门显微镜揭示。我们根据短期和长时间限制的数值计算来解释我们的发现，并为观察到的现象提供了现象学模型。
We theoretically investigate the mapping of the supercurrent distribution in a planar superconductor-normal-superconductor junction in the presence of a perpendicular magnetic field via the scanning gate microscopy technique. We find that the distribution of counter-propagating supercurrents aligned in Josephson vortices can be mapped by the change of the critical current induced by the tip of the scanning probe, if the flux in the junction is set close to maxima of the Fraunhofer pattern. Instead, when the magnetic field drives the junction to a supercurrent minimum in the Fraunhofer pattern, the superconducting phase adapts, and the tip always increases the supercurrent. The perpendicular magnetic field leads to the formation of Josephson vortices, whose extension for highly transparent junctions depends on the current circulation direction. We show that this leads to an asymmetric supercurrent distribution in the junction and that this can be revealed by scanning gate microscopy. We explain our findings on the basis of numerical calculations for both short- and long-junction limits and provide a phenomenological model for the observed phenomena.
