They use a process called "entanglement swapping" that allows you to create entanglement between two particles that have never interacted. It's described partw

They use a process called "entanglement swapping" that allows you to create entanglement between two particles that have never interacted. It's described partway through this article: http://www.scottaaronson.com/blog/?p=2464 http://www.scottaaronson.com/blog/?p=2464