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Homework Help: Quantum optics - dirac notation

  1. Dec 12, 2011 #1
    1. The problem statement, all variables and given/known data
    Please note i am refering to the above notes

    I basically dont get how the maths works to get
    (eq(25))(eq(22))(eq(24)) = eq(26)

    am i missing something interms of the commutator relations ?
    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Dec 12, 2011 #2


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    Ah, those equations are familiar. Did you try just multiplying through, remembering to keep everything in the right order, and recalling that <1|2> = <2|1> = 0 and <1|1> = <2|2> = 1, and that some of those exponentials will cancel?
  4. Dec 13, 2011 #3
    ^^ yes
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