High-Temperature Superconductivity in Size-Selected Metal Nanoclusters: Gas-Phase Spectroscopy and Prototype Devices for Deposition Studies

Metal nanoclusters, composed of tens to thousands of atoms, display the phenomenon of electronic shell structure. This quantum size effect, with its associated level degeneracy, turns out to be highly propitious for superconductivity. Spectroscopy of free aluminum nanoclusters has revealed a pairing phase transition in their electron density of states at a temperature two orders of magnitude higher than the bulk. In addition to gas-phase research on this new family of high-T c systems, it is important to pursue their use as building blocks for superconducting networks and assemblies. The development of devices suitable for the detection of superconductivity in surface-deposited nanoclusters is outlined.