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"Spooky" Science Points Towards Quantum Computing

Posted by ScuttleMonkey on from the more-success-quantum-theory-has-the-sillier-it-looks dept.

Stony Stevenson writes to tell us that University of Michigan physicists have been able to establish an "entanglement" between two atoms trapped more than a meter apart in different enclosures using light. This shows how two different atoms can have a sort of communication, something Einstein referred to as 'spooky action-at-a-distance'. "By manipulating the photons emitted from each of the two atoms and guiding them to interact along a fibre-optic thread, the researchers were able to detect the resulting photon clicks and entangle the atoms. Professor Monroe explained that the fibre-optic thread was necessary to establish entanglement of the atoms. But the fibre could be severed and the two atoms would remain entangled, even if one were 'carefully taken to Jupiter'."

4 of 294 comments (clear)

  1. Entanglement and black holes... by DESADE · · Score: 5, Interesting

    I've always wondered if we would one day be able to use entangled photons to peer beyond the event of a black hole. Keep one particle in an observable state and send one through the black hole. Something is bound to happen and it might give us some insight into what exists beyond the event horizon. This experiment sounds like a step toward that possibility.

  2. Re:Entanglement and causality? by renoX · · Score: 4, Interesting

    >You can't violate causality, even with quantum entanglement.

    And IMHO, that's the 'weirdest' part: an interaction which an instantaneous non-local effect *but* that cannot be used to communicate faster than C??

    Strange, very strange.

  3. Re:Entanglement and causality? by Graff · · Score: 4, Interesting

    My arm-chair understand of Entanglement suggests that it should violate causality. Quantum entanglement can't violate causality. The reason for this is that entanglement can't transmit information alone, it needs to be performed in conjunction with a classical, non-entangled information channel. This is explained in the No-Communication Theorem. It boils down to the fact that you can't tell the difference between random fluctuations in the particles and the signal you are trying to transmit, in order to separate the two you need to transmit some additional information by classical means. Take a look at this discussion on quantum teleportation.

    The end result is that information transmitted through entanglement travels at the fastest speed allowed by conventional means. Until we create a warp drive that limit is the speed of light.
    --
    Sapere aude!
  4. Re:Entanglement and causality? by scribblej · · Score: 4, Interesting

    People think Quantum Physics is spooky, but I don't get it -- I really don't. Can anyone please explain to me (or point me at a link) that will tell me how this is any different than having two billiard balls, one is red and one is blue. Without looking at them, you put them both into boxes and ship them off to opposite sides of the globe. Now, one box is opened, and the ball is blue. So you know when the other box is opened, the ball they got will be red.

    That's not spooky, bizarre, or even strange. It's not counterintuitive. So how is it different than quantum entanglement? I do not know, but I would like to.