Comparison between GaAs and graphene QHR standards for resistance realisation at SP

We report the first precision QHR measurements at SP using a graphene chip. We compare the results of a resistance calibration using GaAs based chips with the results using a graphene chip. The results agree within a few parts in 109 for calibrations of 100 Ω and 10 kΩ resistors. Consistency checks indicate that the uncertainty is lower with the graphene chip, and the noise level is slightly lower. The measurements with the graphene chip were performed exclusively at 4.2 K, which simplifies the calibration procedure considerably compared with GaAs chips.
EMRP GraphOhm