A programmable quantum current generator based on the application of Ohm's law to quantum voltage and resistance standards has demonstrated a realization of the ampere from the elementary charge with a 10−8 relative uncertainty [J. Brun-Picard et al. PRX 6, 041051, 2016]. Here, we report on improvements of the device leading to a noise reduction of the generated quantized current. The improved quantum current generator is used to calibrate different ammeters with lower measurement uncertainties. Besides, measurements of its quantized current using a calibrated Ultrastable Low-Noise Current Amplifier (ULCA) have shown that the realizations of the ampere at PTB (Physikalisch-Technische Bundesanstalt) and LNE (Laboratoire national de m\'{e}trologie et d'essais) in the range ±50μA agreed to -3.7 parts in 107 with a combined standard uncertainty of 3.1 parts in 107 (coverage factor kc=1).
@article{arxiv.2106.05023,
title = {Improvements of the programmable quantum current generator for better traceability of electrical current measurements},
author = {Sophie Djordjevic and Ralf Behr and Dietmar Drung and Martin Götz and Wilfrid Poirier},
journal= {arXiv preprint arXiv:2106.05023},
year = {2021}
}