Serrier-Garcia L, Cuevas J C, Cren T, Brun C, Cherkez V, Debontridder F, Fokin D, Bergeret F S, Roditchev D
Institut des Nanosciences de Paris, Université Pierre et Marie Curie (UPMC) and CNRS-UMR 7588, 4 place Jussieu, 75252 Paris, France.
Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
Phys Rev Lett. 2013 Apr 12;110(15):157003. doi: 10.1103/PhysRevLett.110.157003. Epub 2013 Apr 9.
The proximity effect between a superconductor and a highly diffusive two-dimensional metal is revealed in a scanning tunneling spectroscopy experiment. The in situ elaborated samples consist of superconducting single crystalline Pb islands interconnected by a nonsuperconducting atomically thin disordered Pb wetting layer. In the vicinity of each superconducting island the wetting layer acquires specific tunneling characteristics which reflect the interplay between the proximity-induced superconductivity and the inherent electron correlations of this ultimate diffusive two-dimensional metal. The observed spatial evolution of the tunneling spectra is accounted for theoretically by combining the Usadel equations with the theory of dynamical Coulomb blockade; the relevant length and energy scales are extracted and found in agreement with available experimental data.
在扫描隧道光谱实验中揭示了超导体与高扩散二维金属之间的邻近效应。原位制备的样品由通过非超导原子级薄无序Pb润湿层相互连接的超导单晶Pb岛组成。在每个超导岛附近，润湿层具有特定的隧穿特性，这反映了邻近诱导超导与这种极限扩散二维金属的固有电子关联之间的相互作用。通过将乌萨德尔方程与动态库仑阻塞理论相结合，从理论上解释了观察到的隧穿光谱的空间演化；提取了相关的长度和能量尺度，并发现与现有实验数据一致。
