Proposal for new experimental schemes to realize the Avogadro constant

Abstract

We propose two experimental schemes to determine and so to realize the Avogadro constant $N\_A$ at the level of 10${}^{-7}$ or better with a watt balance experiment and a cold atom experiment measuring $h/m(X)$ (where $h$ is the Planck constant and $m(X)$ the mass of the atom $X$). We give some prospects about achievable uncertainties and we discuss the opportunity to test the existence of possible unknown correction factors for the Josephson effect and quantum Hall effect.