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Nanowire device slips ahead in race to a primary standard for current

A phenomenon known as quantum phase slip has been used to generate a current by moving pairs of electrons through an ultrathin wire. The feat is good news for efforts to pin down the standard unit of current.
  1. Masaya Kataoka

    1. Masaya Kataoka is at the National Physical Laboratory, Teddington TW11 0LW, UK.

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The standard unit of electric current, the ampere, is one of the seven base units in the International System of Units. But measuring a current exactly in amperes is not an easy task. In fact, in 1990, attempts to pin down the ampere were abandoned in favour of using the volt (which measures voltage) and the ohm (which measures electrical resistance) as primary electrical units1 (see go.nature.com/3umryol). Writing in Nature, Shaikhaidarov et al.2 now report a method for producing current in discrete, measurable steps by irradiating a wire that is a few thousand times thinner than a human hair. The approach could be used as a quantum current standard for the ampere — providing a missing piece in electrical metrology.

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Nature 608, 40-41 (2022)

doi: https://doi.org/10.1038/d41586-022-01994-4

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Competing Interests

The author declares no competing interests.

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