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Quantum Measurement Division

Welcome

The Quantum Measurement Division (QMD) provides the physical foundation for the International System of Units (Système International d'Unités or SI), colloquially referred to as the metric system.

We achieve this through precision measurements of various fundamental constants, realization of resistance and voltage through the quantum hall effect and Josephson effect respectively, and through our determination of the best values of the fundamental constants done under the auspices of the Task Group on Fundamental Constants of the Committee on Data for Science and Technology (CODATA, an interdisciplinary unit of the Scientific Committee of the International Council for Science).

The division is currently heavily engaged in the redefinition of the SI that is expected to occur in 2018. We support this effort through R&D and through interactions with the International Bureau of Weights and Measures (BIPM) and its consultative committees including the Consultative Committee for Units (CCU), the Consultative Committee for Electricity and Magnetism (CCEM), and the Consultative Committee for Mass and Related Quantities (CCM).

As part of this effort, NIST is building a new Watt Balance which − prior to the redefinition −will be used to make one final precision measurement of the Planck constant. After the redefinition, it will become the means for the realization of the kilogram in the United States.

The planned redefinition of the SI in 2018 will achieve the goal of turning the SI into a system based on fundamental constants and properties of nature. In fact, the new redefined SI will be largely based on quantum mechanics and its generalizations. including quantum electrodynamics.

As such, the strategy of the QMD is to:

  • investigate and exploit quantum behavior to create measurement tools and capabilities at and beyond the standard quantum limit
  • explore the basic capabilities of complex quantum systems to better understand what future quantum technologies will allow us to measure, compute, and simulate
  • exploit this knowledge to create the foundation to realize and disseminate mass, force, and electrical quantities and improve our ability to realize these quantities
  • disseminate these quantities from first principles, through specially developed instruments and methodologies, or through scaling that minimizes the loss of accuracy of the various technologies involved relative to the best available quantum or classical technology
  • to create critically evaluated data relevant to both fundamental constants and atomic properties
Contact

General Information:

Carl Williams
Division Chief
301-975-3531 Telephone
301-926-3972 Facsimile

Email: carl.williams@nist.gov

100 Bureau Drive, M/S 8420
Gaithersburg, MD 20899-8420