Here’s a fascinating new development from the world of quantum physics: physicists (based in Boulder) were able to set up a quantum system where the mechanical vibrational states of two separated systems were entangled.
Jost and colleagues entangled the vibrational motions of two separated mechanical oscillators, each consisting of one beryllium and one magnesium ion. Each pair behaves like two objects connected by a spring 4 micrometers (millionths of a meter) long, with the beryllium and magnesium moving back and forth in opposite directions, first toward each other, then away, then back again. The two pairs perform this motion in unison, even though they are 240 micrometers apart and are located in different zones of an ion trap.
To entangle the motion of the two oscillators, the NIST group first placed four ions together in one trap zone in a particular linear order (Be-Mg-Mg-Be), and entangled the internal energy states of the two beryllium ions. The team then separated the four ions into two pairs, with each pair containing one of the entangled ions. Finally, the scientists transferred the entanglement from the beryllium ions’ internal states to the oscillating motions of the separated ion pairs.