Physicist unveils plan for entangling massive objects

(Phys.org)—Roman Schnabel, a physics professor at the Max Planck Institute for Gravitational Physics has published a paper in the journal Physical Review Letters outlining a plan for entangling two "massive" objects. He and his team are still working on a way to actually carry out the plan, but if successful, the group would succeed in entangling two 0.1 kg mass mirrors, which would represent a much larger example of entanglement than anything that has come before—up till now the largest objects to be entangled were of micron size.


Entanglement is of course the odd and perhaps a little eerie situation where two or more objects are connected in a way that cannot yet be explained—measuring one causes the other to be impacted instantaneously. The phenomenon was predicted back in the 1930's by Einstein, Podolsky, and Rosen. Over the years, scientists have developed ways to cause particles and then tiny objects to become entangled, but it still was not clear if a way could be found to cause objects large enough to be governed by classical physics to be entangled. In his paper, Schnabel draws up a means of achieving that goal, and notes that he believes it can be done.

Schnabel's plan is to place two of the mirrors in a Michelson-type interferometer in such a way as to have both sides of both mirrors hit by light that is sent in. The mirrors would also be placed in the interferometer in a way that would allow them to oscillate when struck by the light. This would allow for momentum to be transferred between the mirrors and the light. The mirror oscillations would then have an impact on the phase of the reflected light, causing the momentum and the light to become entangled. At that point, the entanglement could be "swapped" to the mirrors, causing them to be entangled, by measuring the light beams as they exit.

http://phys.org/news/2015-08-physicist-unveils-entangling-massive.html