Researchers from a UK-led collaboration have successfully demonstrated a crucial principle that could support the next generation of quantum sensors, marking an important milestone in the development of large-scale quantum detection systems.
results, Published in the magazine natureIt provides the first experimental evidence that technology designed to eliminate disruptive background noise can work effectively under realistic conditions.
This breakthrough is expected to support the future deployment of advanced atomic interferometers capable of exploring some of the universe’s greatest secrets.
The research forms part of the Atomic Interferometer Observatory and Network (AION), a major UK initiative funded through UK Research and Innovation (UKRI). Quantum techniques for fundamental physics program.
The project aims to build powerful new tools capable of searching for and discovering previously inaccessible dark matter Gravitational waves.
Solve the main challenge of quantum detector development
Noise is one of the biggest obstacles to large-scale quantum detectors. Signals associated with phenomena such as dark matter or gravitational waves are incredibly weak and can be easily masked by interference generated within the measurement system.
Atomic interferometers, at the heart of the AION program, rely on lasers to manipulate ultracold atoms into a quantum superposition state.
This allows the atoms to effectively occupy two paths simultaneously before recombining, enabling scientists to measure very small perturbations with exceptional precision.
However, the lasers used in these experiments emit phase noise that is often much stronger than the signals the researchers are trying to detect.
To address this problem, the scientists proposed using two separate interferometers operating on the same baseline. By comparing their measurements, the common noise can be canceled out, allowing real signals to emerge.
While this concept has long been viewed as essential for future quantum detector designs, it has never before been demonstrated under conditions representative of real-world operation.
The table experiment gives clear results
The research team built a prototype system at the Imperial Ultracold Strontium Laboratory using two physically separated clouds of ultracold strontium-87 atoms controlled by a single ultra-stable laser.
To replicate the challenging conditions expected in future long-baseline instruments, the scientists deliberately introduced large amounts of additional noise into the experiment.
The result was exciting. Individual interferometers became virtually unusable, with their signals completely overwhelmed. However, when measurements from both devices were compared, the researchers succeeded in recovering a clear signal and achieved performance only limited by the fundamental laws of quantum physics.
The team then added an artificial oscillating signal designed to mimic the effects of a passing gravitational wave or dark matter field. Despite the extreme noise conditions, the signal remained clearly detectable using the differential measurement approach.
Building the UK’s first large-scale atomic interferometer
The breakthrough is supported by plans for AION-10, an atomic interferometer with a diameter of 10 metres, which is expected to be installed inside the Beecroft Building at the University of Oxford. Data collection is currently targeted before the end of the decade.
The Science and Technology Facilities Council (STFC) plays an important role in the project beyond overseeing funding. Its Technology Department, together with RAL’s aerospace and particle physics specialists, is responsible for the key engineering and scientific components of the device.
Among these contributions is the development of the detector’s main tower structure, which will support the central experimental device and its associated units.
The quantum sensors team at RAL Space is also developing the ultra-cold strontium atom source required for the experiment. The process involves heating the strontium to form vapor before cooling the atoms with a precise laser and trapping them in a very high vacuum environment.
Meanwhile, particle physicists at STFC design magnetic shielding systems designed to protect atoms from external interference during measurements.
Open a new window on the universe
The successful demonstration provides the first direct validation of the fundamental concept behind long-baseline quantum detector technology, helping to overcome one of the most important technical hurdles facing the field.
AION is also linked to broader international efforts, including the MAGIS program at Fermilab and future projects proposed at CERN. Together, these initiatives aim to extend the range of atomic interferometry techniques over much greater distances.
If successful, future quantum detection networks could explore gravitational wave frequencies beyond the reach of current observatories, providing new opportunities to search for previously unknown forms of matter.
Scientists believe that these technologies could eventually reveal entirely new aspects of the universe that remain hidden today.
