Institute of Physics, The Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
J Phys Condens Matter. 2010 Feb 17;22(6):065701. doi: 10.1088/0953-8984/22/6/065701. Epub 2010 Jan 21.
Using low temperature scanning tunnelling microscopy/spectroscopy (STM/STS) we have investigated the vortex behaviours of two-dimensional superconducting Pb films at different thicknesses. STS at the vortex core shows an evolution of electronic states with film thickness. Transition from the clean limit to the dirty limit of superconductivity is identified, which can be ascribed to the decreased electronic mean free path induced by stronger scattering from the disordered interface at smaller thicknesses. A magnetic field dependent vortex core size is observed even for such a low- κ superconductor. The weak pinning induced by surface defects leads to the formation of a distorted hexagonal vortex lattice.
利用低温扫描隧道显微镜/光谱学（STM/STS），我们研究了不同厚度二维超导 Pb 薄膜的涡旋行为。在涡旋核心处的 STS 显示出电子态随薄膜厚度的演化。从超导的清洁极限到肮脏极限的转变被识别出来，这可以归因于较小厚度下无序界面更强的散射导致电子平均自由程减小。即使对于这种低 κ 超导体，也观察到了磁场依赖的涡旋核尺寸。表面缺陷引起的弱钉扎导致了扭曲的六边形涡旋晶格的形成。
