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Bell States

  1. Sep 23, 2010 #1
    Towards the end of http://www.youtube.com/watch?v=IAgV-LKTiMI&feature=channel" video at 54:55, the professor defines the four possible states of two entagled electrons as follows:

    |0,0> = |u,d> - |d,u>
    |1,1> = |u,u>
    |1,0> = |u,d> + |d,u>
    |1,-1> = |d,d>

    |u,u>, |u,d>, |d,u>, |d,d>
    form the 4 dimensional basis in the space of the total spin of the two electrons.

    This doesn't seem to jive with the four bell states as defiend on wikipedia http://en.wikipedia.org/wiki/Bell_state" [Broken].

    For example, the first triplet state of the total spin as defined above |1,1> is an eigenstate of the |u,u> state and doen't need to be superposed. However, every Bell State as defined by wikipedia is a superposition of two states. What am I missing?

    Also, which of the four Bell States is the singlet state?
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Sep 24, 2010 #2
    Do you have a precise mathematical definition of a "Bell state" for this particular case? If so, what is it? If not, what do you think it can be?
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