Spooky quantum connection quantified for multiple particles

‘Entanglement entropy’ measurements provide clues to properties of complicated systems

rubidium atoms

EVERYWHERE ENTANGLEMENT  Each green dot in this cloud is a rubidium atom. Harvard physicists isolated sets of four atoms and measured the degree of entanglement between the atoms.

Markus Greiner

A first-of-its-kind measurement has quantified a mysterious quantum bond shared by several particles rather than just two.