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A joint research laboratory on cryogenic metrology created by LNE and TIPC/CAS

LNE and The Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences (TIPC /CAS) signed an agreement for scientific cooperation in the field of temperature.

This signature, in the kindly presence of Dr XIANGLI Bin Vice President of the Chinese Academy of Sciences and Thomas Grenon, Managing Director of LNE marks the constitution of the Joint Research Laboratory TIPC-LNE International Laboratory of Cryogenic Metrology Science and Technology.

CPEM 2018 : Summary paper submission and registration are now open!

The Conference on Precision Electromagnetic Measurements (CPEM) is the most important scientific and technological conference in the domain of electromagnetic measurements at the highest accuracy levels. This conference covers the frequency range from direct current (DC) to the optical region.

2018 is expected to be a watershed year in the history of the international system of units (SI), with the adoption of the new definitions for the kilogram, the ampere, the kelvin and the mole. All the SI units will then be based on a set of seven defining constants. CPEM 2018 will provide a privileged opportunity to mark this milestone of the SI through a natural focus on quantum devices that relate electrical measurement standards to fundamental constants of physics.

CPEM 2018 will also be the place to share knowledge on research in electromagnetic metrology focused on present and future challenges regarding industry and society in sectors such as Energy, Information and Communication Technology (nanomaterials, internet of things …), quantum engineering, Industry 4.0, etc.

Call for 2-page summary papers :
Authors are invited to submit 2-page summary papers in English to be considered for oral or poster presentations at CPEM 2018. The deadline for submissions is January 19, 2018.
Abstracts of the accepted 2-page summary papers will be available online. The accepted 2-page summary papers will be distributed at the Conference and referenced on IEEE Xplore after the Conference.
Papers must be submitted through the online submission portal.

CPEM attracts numerous attendees from national metrology institutes as well as researchers from university laboratories specialized in precision measurements, metrologists from industrial and government standards laboratories and representatives of manufacturers of the highest accuracy standards and measurement instruments.

Registration :
Register for the Conference through on the secure online registration portal.

Visit the CPEM 2018 website for full details.

First 10-8 accurate quantum realization of the Ampere

Although the electrical current is usually described by a flow of elementary charges per second, the definition of the ampere, unit of electrical current in the International System of units (SI), is still based on an electromechanical force expressed in newtons. This definition set in 1948 limits the accuracy of electrical measurements and of derived quantities. A major overhaul, planned in 2018, aims at put SI units in line with modern physics to reduce measurement uncertainties, by fixing the value of certain fundamental constants, among them the elementary charge that will be used to define the ampere. In 2016, researchers from the Laboratoire national de métrologie et d’essais (LNE) developed a quantum current standard, universal and practical, able to generate for the first time, currents of values in a range from microampere to milliampere that are accurately linked to the elementary charge with the targeted relative uncertainty of 10 parts in a billion.

This breakthrough relies on an error-free application of the Ohm’s law to the highly-accurate quantum standards of resistance and voltage, based on two macroscopic quantum effects only linked to fundamental constants, the quantum Hall effect and the Josephson effect, occurring in two-dimensional semiconductors and superconductors respectively.

This novel quantum current generator improves the accuracy of current standards by two orders of magnitude and paves the way to fully quantum-based electrical measurements in the SI.

This research was published in the Physical Review X (PRX) journal of the American Physical Society (APS): J. Brun-Picard, S. Djordjevic, D. Leprat, F. Schopfer and W. Poirier, "Practical Quantum Realization of the Ampere from the Elementary Charge", Phys. Rev. X, 6, 041051 (2016).

It was also covered by a Viewpoint commentary "A New Era for the Ampere", in the on-line Physics journal of the APS.

Graphene, a revolutionary material for metrology and the International System of units

A French team of researchers based at National Metrology and Testing Laboratory (LNE) and various laboratories at National Center for Scientific Research (CNRS) has found that graphene, which led to the 2010 Nobel Prize in Physics, can be used to realize a primary standard of electrical resistance based on the quantum Hall effect, which operates with state-of-the-art accuracy and in experimental conditions much more practical than that required by conventional semiconductors.

These results, published in Nature Nanotechnology on 7 September 2015, pave the way to a broader use of the universal and accurate quantum electrical standards to the benefit of Science and Industry. They also contribute to the redefinition of the International System of units, including the redefinition of the kilogram. Moreover, they proof that graphene is now mature for a very demanding application.

Preliminary works were published in Nature Communications in April 2015 (Nat. Commun. 6, 6806 (2015)).

Research groups involved :

This research received funding from the French Agence Nationale de la Recherche (ANR), and was partly supported within the European Metrology Research Programme (EMRP) project SIB51, GraphOhm.

R. Ribeiro-Palau, F. Lafont, J. Brun-Picard, D. Kazazis, A. Michon, F. Cheynis, O. Couturaud, C. Consejo, B. Jouault, W. Poirier and F. Schopfer « Quantum Hall resistance standard in graphene devices under relaxed experimental conditions » paru dans Nature Nanotechnology le 7 Septembre 2015. http://dx.doi.org/10.1038/nnano.2015.192

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