New technique to detect dark matter using atomic clocks and lasers

University of Queensland PhD student Ashlee Caddell co-led a study in collaboration with Germany's metrology institute Physikalisch-Technische Bundesanstalt (PTB), that searched for dark matter using atomic clocks and cavity-stabilized lasers.

"Despite many theories and experiments scientists are yet to find dark matter, which we think of as the 'glue' of the galaxy holding everything together," Ms Caddell said.

"Our study used a different approach -- analysing the data from a network of ultra-stable lasers connected by fibre optic cables, as well as from two atomic clocks aboard GPS satellites.

"Dark matter in this case acts like a wave, because its mass is very very low.

"We use the separated clocks to try to measure changes in the wave, which would look like clocks displaying different times or ticking at different rates, and this effect gets stronger if the clocks are further apart."

The researchers were able to search for forms of dark matter that have been invisible in previous searches because it emits no light or energy.

"By comparing precision measurements across vast distances, we identified the subtle effects of oscillating dark matter fields that would otherwise cancel themselves out in conventional setups," Ms Caddell said.

"Excitingly, we were able to search for signals from dark matter models that interact universally with all atoms, something that has eluded traditional experiments."

UQ physicist and co-author Dr Benjamin Roberts said the study brings researchers closer to understanding one of the universe's most elusive and fundamental components.

"Scientists will now be able to investigate a broader range of dark matter scenarios, and perhaps answer some fundamental questions about the fabric of the universe," Dr Roberts said.

"This work also highlights the power of international collaboration and cutting-edge technology, using PTB's state-of-the-art atomic clocks and UQ's expertise in combining precision measurements and fundamental physics."