Superconductivity in a single-C 60 transistor

Abstract

Single-molecule transistors are currently attracting enormous attention as possible quantum information processing devices. An intrinsic limitation to their prospects, however, is associated with the presence of a small number of quantized conductance channels, each channel with a high access resistance of at best RK/2=h/2e2=12.9 k. However, when the contacting leads become superconducting, long-range correlations can extend throughout the whole system by means of the proximity effect. This not only lifts the resistive limitation of normal-state contacts, but further paves the way to probe electron transport through a single molecule. Here we demonstrate the realization of superconducting single-molecule transistors involving a single C 60 fullerene molecule. In the past few years, we have seen gate-controlled Josephson supercurrents induced in the family of low-dimensional carbon structures such as flakes of two-dimensional graphene and portions of one-dimensional carbon nanotubes. The present study, involving a full zero-dimensional fullerene, completes the picture. © 2009 Macmillan Publishers Limited. All rights reserved.