Graphene joins the race to redefine the ampere

A new joint innovation by the University of Cambridge and the National Physical Laboratory (NPL), the UK's National Measurement Institute, could pave the way for redefining the ampere in terms of fundamental constants of physics. Graphene is constantly revealing exciting new applications and as our understanding of the material advances rapidly, we seem able to do more and more with it - Malcolm Connolly The world's first graphene single-electron pump (SEP), described in a paper , provides the speed of electron flow needed to create a new standard for electrical current based on electron charge. The international system of units (SI) comprises seven base units (the metre, kilogram, second, Kelvin, ampere, mole and candela). Ideally these should be stable over time and universally reproducible. This requires definitions based on fundamental constants of nature which are the same wherever you measure them. The present definition of the Ampere, however, is vulnerable to drift and instability. This is not sufficient to meet the accuracy needs of present and certainly future electrical measurement.