Entangled atomic clouds separated in space boost measurement precision

Researchers have demonstrated a novel quantum measurement technique that uses entangled atomic clouds separated in space to enhance precision in sensing spatial variations of physical fields. Traditionally, quantum noise and uncertainty limit the accuracy of measurements at very small scales, especially when probing how quantities like electromagnetic fields change across different locations. Previous entanglement-based improvements were confined to atoms kept together in a single location, restricting measurements to one point. This study overcame that limitation by first entangling a single ultracold atomic cloud and then dividing it into two or three spatially separated clouds, preserving the entanglement despite the separation. This approach enabled the atomic clouds to act as a single quantum system, reducing quantum uncertainty and common disturbances across all clouds. The experiment involved atoms cooled to near absolute zero, where their spins respond sensitively to electromagnetic fields. By distributing entangled atoms across multiple locations, the researchers could measure spatial variations in the field with greater accuracy than previously possible. They also developed the theoretical framework to describe and optimize such multi