Improvements of the programmable quantum current generator for better traceability of electrical current measurements

Abstract

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 métrologie et d'essais) in the range $\pm 50$ $\mu$A agreed to -3.7 parts in $10^7$ with a combined standard uncertainty of 3.1 parts in $10^7$ (coverage factor $k_{\mathrm{c}}=1$).

Accepted in Metrologia

References in corpus (9)

• Single-electron current sources: towards a refined definition of ampere
• Evidence for universality of tunable-barrier electron pumps
• Practical quantum realization of the ampere from the electron charge
• Validation of the ultrastable low-noise current amplifier as travelling standard for small direct currents
• The ampere and the electrical units in the quantum era
• A programmable quantum current standard from the Josephson and the quantum Hall effects
• Inter-laboratory nanoamp current comparison with sub-part-per-million uncertainty
• Quantum mechanical current-to-voltage conversion with quantum Hall resistance array
• A resistance bridge based on a cryogenic current comparator achieving sub-$10^{-9}$ measurement uncertainties

Cited by in corpus (1)

• A primary quantum current standard based on the Josephson and the quantum Hall effects