Applications of Quantum Entanglement

If the Manning brothers were quantum physicists as well as NFL quarterbacks, one of them could win his game's opening coin toss every time. The night before they played, the brothers would take two coins from a special quantum box to use the next day. If Peyton's game came first, after learning the outcome of his coin toss, he would know without a doubt how his brother's coin would land. Say Peyton's came up heads; he could text "tails" to his little brother. Eli would correctly call tails in his later game and win the toss (not that it would do the Giants much good).

Such a creepy connection of the fates of far apart coins does not yet threaten the integrity of football. But in the microworld, where the players are atoms and photons, this long-distance connection — technically called quantum entanglement — is as real as instant replay. In fact, entanglement is at the very heart of reality. No mere quantum quirk of interest only to physicists, its peculiar possibilities have caught the attention of investment bankers and information entrepreneurs.

"We believe that there's a second quantum revolution going on right now," says physicist Chris Monroe of the Joint Quantum Institute at the University of Maryland in College Park.…