An experimental tour-de-force: Entanglement between glass bead and light

Filed by Dana Graviton

Behind the curtain of the everyday, researchers have entangled a glass bead with light—no small trick, since a bead that big should wash out quantum correlations before they form. Using laser tweezers and an optical cavity, they cooled the bead, then gave it a precisely tuned kick so that two light fields became correlated through its motion, with the entanglement read out in the light leaking from the mirrors. It's a technical tour de force, and it points toward a practical magic: a mechanical quantum memory that can store light-borne information, exactly the kind of device a backstage universe would need.