A team of international scientists has proposed a new method to detect dark matter using atomic clocks and a network of optical-cavity lasers. This innovative approach could provide fresh insights into one of the universe’s greatest mysteries.
Harnessing Atomic Clocks and Lasers
Atomic clocks, known for their extreme precision, use atomic vibrations to measure time and are commonly deployed in GPS satellites. Optical-cavity lasers, on the other hand, trap light between highly reflective mirrors, stabilizing their frequency for precise measurements, particularly in high-speed fiber networks.
According to the latest study, these technologies can function as sensors, detecting tiny variations in fundamental constants like electron mass. These variations are thought to be caused by oscillating dark matter fields. “Dark matter in this case acts like a wave, because its mass is very, very low,” explained Ashlee Caddell, a PhD student at the University of Queensland (UQ) and a co-author of the study.
Using Distant Sensors for Better Detection
Traditional dark matter detection methods often rely on sensors positioned in the same location, making it difficult to distinguish certain effects. If the dark matter wave interacts symmetrically with multiple sensors, its effects can cancel out, limiting the accuracy of measurements.
READ MORE: The 2°C Climate Goal: A Dead End According to Scientists
To overcome this issue, researchers separated their sensors by vast distances. “By comparing precision measurements across large distances, we identified the subtle effects of oscillating dark matter fields that would otherwise cancel themselves out in conventional setups,” said Caddell.
The team analyzed two datasets:
- Optical cavity laser measurements connected by a 1,380-mile (2,220 km) fiber link, which detected spatial fluctuations in the dark matter field.
- Timing data from microwave atomic clocks aboard GPS satellites, which revealed temporal fluctuations in the dark matter field.
Setting New Limits on Dark Matter Interactions
By analyzing frequency ratios from lasers and atomic clocks, the researchers searched for oscillations with periods ranging from two to 105 seconds, corresponding to dark matter particle masses between 10⁻¹⁹ and 2 × 10⁻¹⁵ electron volts (eV). This enabled them to place the first constraints on electron-mass variations induced by ultra-light dark matter at frequencies below 1 Hz.
Previously, no experiment had directly tested whether dark matter could cause oscillations in electron mass at such low frequencies. The findings help define a range where such effects are either too small to detect or nonexistent.
Moreover, the study sheds light on how dark matter waves may interact with ordinary matter, particularly electrons. “Excitingly, we were able to search for signals from dark matter models that interact universally with all atoms, something that has eluded traditional experiments,” Caddell noted.
Physicist Benjamin Roberts, another co-author from UQ, emphasized the significance of the study: “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.”
This groundbreaking approach could pave the way for new discoveries in dark matter research, potentially bringing us closer to understanding this elusive cosmic phenomenon.
