Physicists from the Russian Quantum middle (RQC),MIPT, the Lebedev Physical Institute, and L'Institut d'Optique (Palaiseau,France) have devised a method for creating a special quantum entangled state. This state enables producing a tall-precision ruler capable of measuring large distances to an accuracy of billionths of a metre. The results of the study have been published in Nature Communications.
Source: phys.org