This Sydney professor is helping to redefine the humble second

Whereas cesium’s tick is measured in gigahertz, the tick of an optical-atomic clock is measured in hundreds of terahertz – a speed differential that presents its own problems, as explained to Watch by Michael Biercuk, professor of quantum physics and quantum technology at the University of Sydney.

Ion traps in Biercuk’s lab at Sydney University, used in building ultra-precise atomic clocks in the microwave and optical regime, one form of technology competitive in redefining the second.

Combing it

How do you turn that into a usable tick? This is the issue Biercuk identifies, explaining: “The cesium rate is very close to the current clock rates in modern technology and computer chips, so we can make electronics link very closely. But with a tick that’s hundreds of terahertz, there needs to be a bridge.”

That bridge is an “optical frequency comb”, a laser that spits out light in pulses. The rate at which it’s blinking on and off converts things to a usable but very stable frequency in the gigahertz range.

Biercuk: “Being able to put the two together – optical clock and comb – means we can have very stable and very precise atomic clocks that can also be technologically relevant. It’s why we have this interest in the redefinition of the second.”

And the practical benefits of this complex process? “Even though it sounds esoteric, something that doesn’t matter to anybody, it’s directly linked to having a trusted standard. . . How do you know your liter of gas is a liter of gas?

“It’s a key part of how mobile applications work, how the whole internet works, with direct flow-down effects into things that we experience every day – financial transactions, network synchronization and GPS localization. With a more precise tick rate, we can position ourselves more accurately.”

And, Biercuk points out, given that standards directly affect pretty much everything in the economy, it’s also likely that, along with better life experiences, any new definition of the second will lead to unimagined commercial opportunities. That’s sure to grab more than a second’s attention.

The August issue of AFR Magazine – plus the 36-page Watch special – is out on Friday, July 29 inside The Australian Financial Review. Follow AFR Mag on Twitter and Instagram.

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