NIST researchers have developed advanced graphene-based quantum Hall effect (QHE) devices that significantly improve electrical resistance standards. These devices, which use graphene instead of traditional semiconductors like GaAs, offer several advantages:
1. Simpler operation: Graphene-based QHE devices require less complex infrastructure compared to GaAs-based devices, making them easier to use in various settings.
2. Expanded parameter space: Graphene devices can operate at lower magnetic fields, higher temperatures, and larger currents, allowing for more flexible and accessible resistance measurements.
3. Cost and complexity reduction: As graphene technology matures, it promises to lower the cost and complexity of resistance standards and associated measurement equipment.
NIST has been using epitaxial graphene in its electrical resistance dissemination service for several years, with a focus on optimizing technology and fabrication processes. Current research aims to further improve these devices and expand their capabilities, such as developing graphene array devices to reduce dependency on artifact standards and creating quantized current sources.
Collaborations with academic, industry, and government partners are crucial to advancing graphene-based QHE devices and their applications in electrical standards and metrology. The development of these devices aligns with the global adoption of the quantum SI in 2019 and the ongoing need for innovative technologies in electrical unit dissemination.
Source: https://www.nist.gov/programs-projects/quantum-conductance
Keywords: graphene, quantum Hall effect, metrology, SI traceability, quantized resistance
