The vibrational motions of two separated mechanical oscillators, each consisting of one beryllium and one magnesium ions, have been found to be entangled, even though they are 240 micrometers apart and located in different zones of an ion trap, physicists at the National Institute of Standards and Technology have demonstrated.

The research provides insights into where and how classical objects may exhibit unusual quantum behavior and suggests techniques to scale up trapped-ion technology to potentially build quantum computers.