Accurate graphene quantum Hall arrays for the new International System of Units.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36376308.
- Also identified by DOI 10.1038/s41467-022-34680-0 and PMC identifier 9663594.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Graphene quantum Hall effect (QHE) resistance standards have the potential to provide superior realizations of three key units in the new International System of Units (SI): the ohm, the ampere, and the kilogram (Kibble Balance). However, these prospects require different resistance values than practically achievable in single graphene devices (~12.9 kΩ), and they need bias currents two orders of magnitude higher than typical breakdown currents I<sub>C</sub> ~ 100 μA. Here we present experiments on quantization accuracy of a 236-element quantum Hall array (QHA), demonstrating R<sub>K</sub>/236 ≈ 109 Ω with 0.2 part-per-billion (nΩ/Ω) accuracy with I<sub>C</sub> ≥ 5 mA (~1 nΩ/Ω accuracy for I<sub>C</sub> = 8.5 mA), using epitaxial graphene on silicon carbide (epigraphene). The array accuracy, comparable to the most precise universality tests of QHE, together with the scalability and reliability of this approach, pave the road for wider use of graphene in the new SI and beyond.