Fisher information and entanglement of non-Gaussian spin states

Abstract

Subtle entanglement in an atomic cloud In the quantum world, atoms can be correlated with each other—“entangled”—which reduces the uncertainty in the knowledge of some of their properties. Physicists then use this reduced uncertainty to perform precision measurements. Strobel et al. made an unusual type of entangled state consisting of hundreds of ultracold Rb atoms. These methods may in the future be able to generate states that will be more useful in precision measurement. Science , this issue p. 424