NIST researchers have developed a new method to produce large, uniform graphene sheets that could revolutionize quantum Hall resistance standards. Graphene, a one-atom-thick carbon material, could replace traditional semiconductor-based standards with simpler, cheaper devices.
Key points:
– Graphene devices could achieve same accuracy as current GaAs standards
– NIST plans to offer graphene QHE standard as a Standard Reference Material within 1-2 years
– Graphene devices require smaller magnetic fields, higher temperatures, and simpler cooling systems
– Graphene sheets are larger, more uniform, and have higher electron mobility than traditional materials
The new method involves heating silicon carbide wafers above 1900°C to create pure graphene sheets. NIST has already made direct comparisons showing graphene devices match GaAs standards to within 1 part in 10^9.
This breakthrough could significantly reduce the cost and complexity of quantum Hall resistance standards, while enabling new applications in computing and quantum information processing.
Source: https://www.nist.gov/news-events/news/2017/05/new-standard-resistance-standards
Keywords: Quantum, Hall, Graphene
