Promotion of superconductivity in magic-angle graphene multilayers

Abstract

Graphene bilayers and trilayers consisting of monolayers twisted at just the right angle have been shown to be superconducting. To acquire a unified understanding of superconductivity in these moiré superlattices, it is desirable to increase the number of known graphene moiré superconductors. Zhang et al. fabricated samples consisting of three, four, and five graphene layers that were twisted with respect to each other in an alternating sequence. These graphene multilayers were coupled to an underlying monolayer of tungsten diselenide. The researchers observed robust superconductivity in all three types of samples, with the superconducting portion of the phase diagram becoming more prominent as the number of layers increased.