Professor Philipp Treutlein of the University of Basel is leading a research effort that is showing how quantum entanglement can be turned into a practical measurement tool rather than a purely theoretical curiosity. Working with collaborators at the Laboratoire Kastler Brossel in Paris, his team has demonstrated that entangled atoms distributed across space can be used to measure physical fields with higher precision and extract multiple parameters at the same time.
Li, Y., Joosten, L., Baamara, Y., Colciaghi, P., Sinatra, A., Treutlein, P., & Zibold, T. (2026). Multiparameter estimation with an array of entangled atomic sensors. Science, 391(6783), 374–378. https://doi.org/10.1126/science.adt2442
Quantum entanglement describes a situation in which two or more particles share a joint quantum state, so that measurements on one are correlated with measurements on the others, even when they are separated by distance. This behavior, first highlighted in the Einstein–Podolsky–Rosen paradox, has been confirmed experimentally and is now a cornerstone of modern quantum physics. While entanglement is often associated with fundamental tests of reality or with quantum computing, it has also become a key resource in quantum metrology, where quantum effects are used to push measurements beyond classical limits.
Professor Philipp Treutlein of the University of Basel stated,
“Our measurement protocols can be directly applied to existing precision instruments such as optical lattice clocks.”
In earlier work, Treutlein and others showed that entangling the spins of ultracold atoms could reduce quantum noise and improve measurement precision. In those experiments, however, all of the atoms were located in the same place. The new study extends this idea by separating the atoms into multiple spatially distinct clouds while maintaining entanglement between them. This step allows researchers to probe how physical quantities vary across space, rather than measuring only a single point.
The experiments rely on clouds of ultracold atoms whose spins behave like tiny magnetic needles. The researchers first generate entanglement among the spins within a single atomic cloud. They then divide this cloud into up to three separate parts, which remain entangled despite being physically separated. Each cloud experiences a slightly different local environment, such as a different strength of an electromagnetic field.
By carefully analyzing the collective spin signals from the entangled clouds, the team was able to reconstruct the spatial variation of the field using far fewer measurements than would be required with unentangled atoms. Entanglement reduces the uncertainty that normally arises from quantum fluctuations and can also suppress noise that affects all sensors in the same way, such as global magnetic disturbances.
Alongside the experimental work, the researchers developed a theoretical framework describing how to optimize measurements when multiple parameters are estimated simultaneously using spatially separated entangled sensors. This was an important step, as previous theories of quantum metrology largely focused on single-location measurements or on estimating only one parameter at a time.
The approach has clear implications for existing precision technologies. Optical lattice clocks, which use atoms trapped in laser-generated lattices to keep time with extreme accuracy, could benefit from entangled measurement schemes that correct for spatial inhomogeneities across the lattice. Even small improvements in clock stability and accuracy can have wide-ranging effects, from global navigation systems to tests of fundamental physics.
Atom interferometers, which measure acceleration and gravity by tracking the motion of atomic wave packets, could also be improved using these methods. In gravimetry, researchers are often interested not only in the average value of gravity but also in how it changes from one location to another. Entangled atomic sensors could provide more precise maps of these variations, with potential applications in geophysics, navigation, and environmental monitoring.
More broadly, the work shows how ideas from quantum foundations can be translated into practical tools for measurement science. By distributing entanglement across space, the researchers have opened a path toward sensor networks that operate at the limits set by quantum mechanics. As experimental control over complex quantum systems continues to improve, such techniques are likely to play an increasing role in how physical quantities are measured and compared across space and time.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
