1. Realization of the quantum ampere using the quantum anomalous Hall and Josephson effects
- Author
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Rodenbach, Linsey K., Tran, Ngoc Thanh Mai, Underwood, Jason M., Panna, Alireza R., Andersen, Molly P., Barcikowski, Zachary S., Payagala, Shamith U., Zhang, Peng, Tai, Lixuan, Wang, Kang L., Elmquist, Randolph E., Jarrett, Dean G., Newell, David B., Rigosi, Albert F., and Goldhaber-Gordon, David
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics ,Quantum Physics - Abstract
By directly coupling a quantum anomalous Hall resistor to a programmable Josephson voltage standard, we have implemented a quantum current sensor (QCS) that operates within a single cryostat in zero magnetic field. Using this QCS we determine values of current within the range 9.33 nA - 252 nA, providing a realization of the ampere based on fundamental constants and quantum phenomena. The relative Type A uncertainty is lowest, 2.30 $\times$10$^{-6}$ A/A, at the highest current studied, 252 nA. The total root-sum-square combined relative uncertainty ranges from 3.91 $\times$10$^{-6}$ A/A at 252 nA to 41.2 $\times$10$^{-6}$ A/A at 9.33 nA. No DC current standard is available in the nanoampere range with relative uncertainty comparable to this, so we assess our QCS accuracy by comparison to a traditional Ohm's law measurement of the same current source. We find closest agreement (1.46 $\pm$ 4.28)$\times$10$^{-6}$ A/A for currents near 83.9 nA, for which the highest number of measurements were made., Comment: 12 pages, 5 figures, 15 pages of supplemental information
- Published
- 2023