DS0305 -

Quantum standards in graphene devices for electrical SI units – GraphMet

Submission summary

Quantum physics revolutionized the electrical metrology by providing universal and reproducible resistance and voltage standards, based on the Planck constant h and the electron charge e only, using the quantum Hall effect (QHE) and the Josephson effect (JE) respectively. Since 1990, these quantum standards have been used for practical realization of the ohm and volt with a greatly improved relative accuracy of 10^-9. These improvements directly benefit to other electrical units such as the ampere and the farad but also to the kilogram. With Coulomb blockade of an elementary charge on an island, quantum mechanics also provides a way to realize a quantum current standard, directly linked to e, in a frequency-driven single-electron source. However, such devices dos not yet compete with QHE and JE devices in terms of accuracy and robustness.
Quantum electrical standards are also going to play another crucial role in the historical evolution of the Système International d’unités (SI) forseen in 2018, in which the SI wil be redefined by fixing the exact numerical values of four constants of nature: h, e, k (the Boltzmann constant) and Na (the Avogadro constant) with no uncertainty. As a consequence, the accuracy of the quantum realizations of the electrical units based on h and e will be greatly improved. Moreover, the three quantum effects will allow direct “mise en pratique” of the new definitions of the kilogram and the ampere based on h and e respectively.
This is capital for the SI, and its dissemination, hence for measurements in general, to have them as accurate, reliable, available and affordable as possible.
Nevertheless, for now, because of their operation conditions (low temperature T, high magnetic field B), which require not only high investment and operational costs (such as liquid helium) but also highly educated operators, the quantum electrical standards have been confined in few big metrology institutes.
In this context, graphene, discovered in 2004, could lead to a major technological revolution: its robust QHE, the possibility it offers for atomically resolved nanostructures, at least, are promising for novel quantum devices with operation conditions compatible with compact, affordable, helium-free, easy-to-handle setups.
The overall objective of the project is to progress in the exploitation of the potential of graphene for realizing such practical and affordable quantum electrical standards in the SI, able to be broadly disseminated to end-users, spreading from national metrology institutes to calibration centres, industry and the scientific community. First, the project will advance the development of the graphene quantum Hall resistance standard in targeting operation in further relaxed conditions, at around B~1 T, T~4 K, beyond the current state-of-the-art recently set by LNE, for integration in a miniaturized cryogen-free setup. Second, following a much more exploratory approach, the project will assess the possibility to implement in graphene and in the same relaxed experimental conditions other quantum electrical standards, namely the Josephson voltage standard and the single-electron current standard, the final goal being to combine the three standards for the ohm, the volt and the ampere on chip, integrated in a single compact cryogen-free setup.
Realizing the above mentioned expected benefits of graphene for the quantum electrical standards is quite challenging in terms of graphene quality, technology and process, as well as in terms of measurements. This challenge will be tackled by experts in growth and nanofabrication experts, as well as experts in quantum transport and metrology.
The progress in the SI traceability of electrical measurements and graphene technology enabled by the project should stimulate and impact both Science and Industry, especially in the fields of innovative graphene based devices, measurement and calibration services, instrumentation, graphene manufacturing and cryogenics.

Project coordination

Félicien SCHOPFER (Laboratoire National de Métrologie et d'Essais)

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.

Partner

INAC Institut Nanosciences et Cryogénie
LPN (CNRS DR IDF SUD) Laboratoire de Photonique et Nanostructures
LPN Laboratoire de Photonique et de Nanostructures
L2C Laboratoire Charles Coulomb
CRHEA Centre de Recherche sur l'Hétéroépitaxie et ses Applications
LNE Laboratoire National de Métrologie et d'Essais
INEEL INSTITUT NEEL

Help of the ANR 623,043 euros
Beginning and duration of the scientific project: September 2016 - 48 Months

Useful links

Explorez notre base de projets financés

 

 

ANR makes available its datasets on funded projects, click here to find more.

Sign up for the latest news:
Subscribe to our newsletter