87Sr Atom Interferometer Rejects 4π Laser Noise, Advancing 1-Hz Wave and Dark Matter Searches
Updated
Updated · Nature.com · Jun 17
87Sr Atom Interferometer Rejects 4π Laser Noise, Advancing 1-Hz Wave and Dark Matter Searches
3 articles · Updated · Nature.com · Jun 17
Summary
A prototype differential atom interferometer using fermionic 87Sr kept quantum-limited sensitivity even after researchers injected several radians of shot-to-shot laser phase noise, validating the noise-cancellation principle needed for long-baseline detectors.
56,623 shots collected over 61.9 hours showed no statistically significant excess differential-phase noise beyond the standard quantum limit: 43.5 mrad per shot and about 258 μrad on the averaged phase.
The setup used two atom clouds separated by 1 mm and a common clock laser; although the added noise completely erased single-interferometer fringes, a maximum-likelihood analysis still recovered the differential phase.
Injected oscillatory signals from 100 μHz to 100 mHz were also recovered under fully phase-randomized conditions, showing the differential scheme can extract coherent signals that a single interferometer would lose.
The result marks a laboratory milestone for proposed kilometer-scale and space-baseline atom interferometers targeting the mid-frequency gap around 0.1 to 10 Hz for gravitational waves and ultralight dark matter.
With key noise problems solved, who will win the international race to build the first kilometre-scale atom interferometer?
What cosmic secrets, hidden between LIGO's and LISA's views, will this new mid-frequency window finally reveal?
Beyond detecting dark matter, how will this quantum technology soon impact industries like defense and underground mapping?
Atom Interferometry at the Standard Quantum Limit: The 87Sr Breakthrough Powering AION’s Next-Generation Gravitational Wave and Dark Matter Search
Overview
In June 2026, the AION project achieved a major breakthrough in quantum sensing by developing a prototype 87Sr atom interferometer. This tabletop device uses the 87Sr clock transition and operates at the Standard Quantum Limit, meaning its measurements are only limited by fundamental atom shot noise. Impressively, the prototype maintains this high precision even when extra laser phase noise is introduced, a key challenge for future large-scale detectors. This success demonstrates that the technology can handle the demanding conditions expected in long-baseline experiments, paving the way for next-generation quantum sensors to explore gravitational waves and dark matter.