Entangled Particles Face Sudden Death

[I]n a paper published today in the journal Science, two physicists show that entangled particles can suddenly and irrevocably lose their connection, a phenomenon called Entanglement Sudden Death, or ESD.

“The degree of information entangled can disappear faster than the information itself,” said Joseph Eberly, a physicist at the University of Rochester, who, along with Ting Yu, co-authored the paper. “It’s completely non-classical physics.”

I don’t do experiments with entangled particles and I haven’t read the paper yet, but I was a little surprised to read that the model up to this point had been that entanglement was lost slowly. I had always gotten the impression that entanglement was much more a binary condition, so you wouldn’t describe particles as being a little bit entangled, any more than you would say someone was a little pregnant. I suspect this has to be tied to the question of how fast a wave function collapses.

Science 30 January 2009:
Vol. 323. no. 5914, pp. 598 – 601
DOI: 10.1126/science.1167343