Superconducting Graphene

Graphene has been impressing scientists for a decade with its exceptional electronic, mechanical, and other properties. Now, it has another claim to fame: The ultrathin carbon material can be a superconductor (Proc. Natl. Acad. Sci. USA 2015, DOI: 10.1073/pnas.1510435112). Superconductors are a small group of materials that conduct electricity without losing energy in the form of heat. A thin-film superconductor such as graphene could be used, in principle, to make nanoscale sensors, quantum computing circuits, and other devices. Andrea Damascelli of the University of British Columbia, Vancouver, and coworkers chilled a monolayer specimen of graphene to cryogenic temperatures and coated the film with lithium atoms. On the basis of photoemission spectroscopy measurements comparing lithium-coated graphene to pristine graphene and to polycrystalline niobium, which is a known superconductor, the team determined that the lithiated graphene superconducts when chilled below a transition temperature of roughly 6 K. The finding confirms recent theoretical studies predicting that graphene can be converted to a superconductor by adsorbing alkali metals on its surface.