High degree of quantum entanglement detected for first time in centimeter-sized crystal of strange metal (opens in new tab)

Many quantum effects can be observed only when a small number of particles is studied—individual atoms, molecules or photons, for example, carefully shielded from the rest of the world. But what about macroscopic objects, consisting of an unimaginably large number of particles? Can they, too, display effects that provide a direct glimpse into the quantum world?