The quantum metrology triangle and the re-definition of the SI ampere and kilogram; Analysis of a reduced set of observational equations

TL;DR

This paper develops a set of observational equations linking fundamental constants to SI units, analyzing the impact of redefinitions of the kilogram and ampere on constant uncertainties, and reviewing quantum metrology triangle experiments.

Contribution

It introduces a reduced set of observational equations that connect fundamental constants to SI units and assesses their implications for SI redefinition.

Findings

The observational equations clarify the relationship between constants and SI units.

Redefinitions influence the uncertainties of h, e, and mu.

Experimental evidence supports the quantum metrology triangle's validity.

Abstract

We have developed a set of seven observational equations that include all of the physics necessary to relate the most important of the fundamental constants to the definitions of the SI kilogram and ampere. We have used these to determine the influence of alternative definitions being considered for the SI kilogram and ampere on the uncertainty of three of the fundamental constants (h, e and mu). We have also reviewed the experimental evidence for the exactness of the quantum metrology triangle resulting from experiments combining the quantum Hall effect, the Josephson effects and single-electron tunnelling.