Current status of the quantum metrology triangle
Abstract
The quantum metrology triangle is a test of the consistency of three quantum electrical standards: the singleelectron tunnelling current standard, the Josephson voltage standard and the quantum Hall resistance standard. This paper considers what is known about each of these effects separately in terms of (1) theory, (2) empirical tests of universality and (3) 'direct' tests involving fundamental constants. The current status of each of the three 'legs' of the triangle is quite different, with the singleelectron leg being the weakest by far. This leads to the conclusion that a recent experimental result for the triangle should be interpreted primarily in terms of corrections to the quantum of charge transferred by singleelectron devices.
 Publication:

Metrologia
 Pub Date:
 February 2008
 DOI:
 10.1088/00261394/45/1/014
 Bibcode:
 2008Metro..45..102K