Superconductivity in Thin Films

For decades, researchers have looked for improved or novel superconducting properties in thin films. In his Perspective, [Chiang][1] highlights the report by [ Guo et al .][2], who show that film thickness can indeed affect superconducting behavior. The experiment was performed on lead films deposited on silicon surfaces. Special care in sample preparation resulted in atomically uniform films with exactly known numbers of atomic layers. The measurements show convincingly that the superconducting transition temperature oscillates with film thickness. The period of oscillation agrees with expectation based on quantum confinement of electrons in the films. [1]: http://www.sciencemag.org/cgi/content/full/306/5703/1900 [2]: http://www.sciencemag.org/cgi/content/short/306/5703/1915