Sat. May 28th, 2022


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The world’s most widely used measurement system, the International System of Units (SI), was redefined in 2019. Since then, it has been necessary to define units from the constants of nature – that is, the rules of nature that are fixed and no uncertainty, such as the speed of light. not in the form of arbitrary references.

This has meant that new research to relate the system’s many units to the constants through experimental realizations has been required.

“The redefinition has created a need for new insights,” says Professor Jukka Pekola.

Researchers at Aalto University have now found a promising new way to connect watts (the power unit) with the constants of nature. They believe their method could point the way to a new power standard; that is, a new way of producing a known amount of current with which other power sources and detectors can be compared.

Researchers have developed a device that converts frequency into current. Frequency is a quantity that can be set with low uncertainty, and therefore it provides a solid basis for a new standard.

“Frequency can be defined very, very precisely. If you can make the other quantities depend on frequency in a known way, then you have a very precise standard,” says Pekola.

Moreover, researchers have discovered that such dependence obeys a simple law of accuracy and robustness.

“These properties increase the chances of using this method by default,” says Marco Marín Suárez, a doctoral candidate.

“Basically, this is a potential new way of realizing a watt, or energy flux, simply by setting previously known quantities,” describes Marín Suárez.

In the experiment, current is produced with a single-electron transistor in its swivel drive. This device was previously proven by Pekola to act as a potential standard for amperes, the device for electric current. It consists of a small metallic island, source and drain lines and a gate electrode, and it can address very small forces.

The road from a proposal to an actually accepted new standard is long. Aalto researchers hope that their work next time will attract the attention of metrologists, who would take it further with more accurate measurements.

“This first experiment was not yet at the metrology level. However, we were able to demonstrate that this principle works, and we have also shown where the main errors come from. It is still unknown whether this will be adopted by the metrology community,” Pekola sums up.

Researchers are now seeking to push their proposals forward by characterizing how well the law of converting frequency into current conforms to their method. This will increase the accuracy with which small forces can be calibrated.

The experiments were performed at OtaNano’s national research infrastructure. Professor Pekola’s group is part of the QTF Center of Excellence and InstituteQ, the Finnish quantum institute.

Moments of silence point the way to better superconductors

More information:
Marco Marín-Suárez et al., An electron turntable for frequency-to-power conversion, Nature nanotechnology (2022). DOI: 10.1038 / s41565-021-01053-5

Provided by Aalto University

Citation: Experiment with turnstiles of single electrons shows way towards new power standard (2022, 20 January) retrieved 20 January 2022 from

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