Sivakov A G, Glukhov A M, Omelyanchouk A N, Koval Y, Müller P, Ustinov A V
B. Verkin Institute for Low Temperature Physics and Engineering, 61103 Kharkov, Ukraine.
Phys Rev Lett. 2003 Dec 31;91(26 Pt 1):267001. doi: 10.1103/PhysRevLett.91.267001. Epub 2003 Dec 23.
Phase-slip lines can be viewed as dynamically created Josephson junctions in a homogeneous superconducting film. In contrast to phase-slip centers, phase-slip lines occur in wide superconducting strips, where the order parameter may vary in two dimensions. We investigated phase-slip lines in two different materials using several methods. We observed Shapiro steps under microwave radiation, which shows that the frequency of the order parameter oscillation is equal to Josephson frequency. A periodic oscillation of a critical current versus the applied magnetic field was found in strips with a hole in the middle. The latter effect provides a clear evidence of macroscopic quantum interference across a phase-slip line. We have used low temperature scanning laser microscopy to visualize the phase-slip lines and to distinguish them from possible local inhomogeneities in the films.
相位滑移线可被视为均匀超导薄膜中动态形成的约瑟夫森结。与相位滑移中心不同，相位滑移线出现在宽超导条带中，其中序参量可能在二维空间中变化。我们使用多种方法研究了两种不同材料中的相位滑移线。我们在微波辐射下观察到了夏皮罗台阶，这表明序参量振荡的频率等于约瑟夫森频率。在中间有孔的条带中发现了临界电流相对于外加磁场的周期性振荡。后一种效应为跨越相位滑移线发生宏观量子干涉提供了明确证据。我们使用低温扫描激光显微镜来可视化相位滑移线，并将它们与薄膜中可能存在的局部不均匀性区分开来。
