Is it possible to measure subtle oscillations caused by dark matter moving through the earth? A Dutch-American physicist team found a new route to the possible first measurement of dark matter. They suspended a microscopic magnet inside a superconducting enclosure, cooled to near absolute zero (0 Kelvin).
With this rather small, but extremely sensitive setup - constructed by Professor Tjerk Oosterkamp and PhD candidate Dennis Uitenbroek of Leiden University - it is possible to detect subtle oscillations believed to be caused by dark matter waves moving through Earth.
Dark matter, although not visible, is believed to make up most of the universe's mass. One theory suggests that ultralight dark matter behaves like a continuous wave, which could exert rhythmic forces that are detectable only with ultra-sensitive quantum instrumentation.
'Our approach brings dark matter detection into a new realm,' says Professor Tunnell of Rice University. 'By suspending a tiny magnet in a frictionless environment, we're giving it the freedom to move if something nudges it.'
This study is a collaboration of Oosterkamp and Uitenbroek and Rice University Professor Christopher Tunnell and PostDoc Dorian Amaral. The experiments all took place in the ultramicroscopy hall at Leiden Institute of Physics, and Rice contributed the theoretical framework and calculations with the data from the experiment.
Media attention in the United States
Results are published in Physics Review Letters.
Article by Sciencenews.com.
Article by APS.org on the 24th of June 2025 (link moet nog komen)
Small-scale research setup
Traditionally, researchers build giant and extremely costly setups to hunt for dark matter. For example, the gravitational wave detector LIGO in the USA is multi-kilometer-scale. The research setup used in Leiden is much, much smaller and cheaper.
The Leiden research setup: much smaller than the kilometer-sized research setups built for researching dark matter 
The Leiden research setup: much smaller than the kilometer-sized research setups built for researching dark matter
More and more precise measurements
Oosterkamp and Uitenbroek monitored the levitated neodymium magnet with incredible precision. 'The length of our levitated magnet is 0.75 mm. If it moves as much as the size of a single hydrogen nucleus, our extremely sensitive sensors will notice it,' explains Dennis Uitenbroek.
Despite this extremely sensitive setup, they did not find evidence of the anticipated dark matter signal, yet. However, they performed the most sensitive force measurement with a levitating magnet ever measured in a hunt for dark matter. The team now plans to increase step-by-step the accuracy of its measurements in the next couple of years. The new setup will incorporate heavier magnets, even more stable levitation, and broader frequency coverage. 'Our future setup won't just listen more closely, it'll be tuned to hear things we've never even tried listening for,' Oosterkamp said.
An entirely new class of measurements
The team is not just testing a new theory but laying the groundwork for an entire class of measurements. Magnetic levitation gives a fundamentally new tool to answer several of the universe's big questions, not only those relating to dark matter but also concerning quantum mechanics.
