The important point here is that after the photons are detected, it is not possible to tell which ion has emitted which photon, and this quantum phenomenon produces entanglement between the ions.

• 这里的重点是，侦测完光子之后，就无法辨别哪个光子是由哪个离子所放出来的，也就是说，这种量子现象会使离子间产生缠结。