Graphene ac metrology - Realization of the resistance unit at ac (GaMe)
| Reference number | |
| Coordinator | RISE Research Institutes of Sweden AB - Mätteknik Borås |
| Funding from Vinnova | SEK 1 300 000 |
| Project duration | December 2020 - December 2023 |
| Status | Completed |
Important results from the project
The purpose of this project is to introduce the use of the quantum Hall effect to impedance measurements at the national measuring institute. The goal is to develop measurement systems and graphene samples for alternating current realization of the resistance unit up to at least 1592 Hz, and to perform comparison measurements against calculable standards. We have fulfilled all the aforementioned aspects in this project, and laid the foundation for achieving a full-scale impedance calibration operation based on only natural constants via the ac quantum Hall effect.
Expected long term effects
The project aims to develop methods to realize of the resistance unit at alternating current. In the short term we wished to be able to reach a measurement uncertainty of the same order of magnitude as the calculable standard can provide. We successfully have achieved this and we aim to present our results in the upcoming conferense CPEM 2024. These first results give us the opportunity to establish ourselves in the field. The ideal goal for future developments is to get as close to the measurement uncertainty level set by the dc quantum Hall effect as possible.
Approach and implementation
The project was carried out in accordance with the plan outlined in the original proposal. We started by improving the technology behind the fabrication of graphene samples adapted for ac measurements. In parallel, we improved the measuring probe and the sample holder. We performed simple test measurements during the development phase and created new iterations of the measurement setup. Finally, more accurate comparison measurements were performed between the ac-graphene sample and a standard resistor calibrated against a calculable standard using an impedance bridge.