Entanglement Warms Up

Entanglement is the strange quantum mechanical link between two separated objects that allows a measurement of one to apparently influence the other. Normally, entangling objects or particles other than photons requires temperatures as low as fractions of a degree Kelvin. But in the 29 October Physical Review Letters, theorists propose a technique for entangling two oscillators--which could be atoms or vibrating pieces of silicon--at higher temperatures. For atoms, the environment could be as warm as 50 degrees Kelvin, they say. By coupling the two oscillators together with the analog of a spring and then causing the strength of the spring to oscillate in time, the entanglement can be made to survive, despite interactions with a high-temperature environment. The team thinks their technique could ease the experimental burden on scientists currently studying entanglement at difficult-to-reach temperatures.