Researchers at Aalto University propose method of transducing frequency to power.

The world’s most commonly used system of measurement, the International System of Units (SI), was redefined in 2019. Since then, units have needed to be defined in terms of the constants of Nature – that is, Nature’s rules that are fixed and of no uncertainty, such as the speed of light – and not in terms of arbitrary references.

This has meant that new research for relating the many units of the system to the constants through experimental realizations has been called for.

“The redefinition has caused a need for new realizations,” says Professor Jukka Pekola.

Researchers at Aalto University have now found a promising new way to link the watt (the unit of power) to the constants of Nature. They believe their method could show the way towards a new power standard, that is, a new way to produce an apriori known amount of power against which other power sources and detectors can be compared.

The researchers have developed a device that converts frequency to power. Frequency is a quantity that can be set with low uncertainty, and therefore it provides a solid basis for a new standard.

Measured power at different device working points (top). Its values are even integer multiples of Δf, hence the plateau structure of this figure. The device (bottom) is constituted by a small metallic island, source and drain leads and a gate electrode. Credit: Aalto University

“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 accurate standard,” Pekola says.

Furthermore, the researchers have discovered that such dependence obeys a simple law with