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Homework Help: Trying to interpret matrix representations of operators

  1. Oct 10, 2013 #1
    Say I have a 3x3 operator Q and I find its eigenvectors and eigenvalues. Now i know that those eigenvectors are the same as eigenfunctions so if i act on them with Q i will get the corresponding eigenvalue.

    What the question im trying to solve asks is, Measure the quantity Q in state where b is given as a 3x1 matrix. I know how to do it mathematically, I just express as a linear combination of my eigenvectors. But I'm trying to interpret what this means. Is the state some state my wavefunction is in and when I measure it, it will be in a state of one of the eigenvectors of Q?

    I am comparing this to Schrodingers cat where before I measure it is in a linear combination of alive and dead and there is a probability that can be alive or dead and when I measure (ie look) the wavefunction collapses to either alive or dead. Am i correct in thinking this way about Q and ?
  2. jcsd
  3. Oct 10, 2013 #2


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    Homework Helper

    yeah, that's right. When they say a measurement of the physical quantity associated with Q, that means the state suddenly jumps into one of the eigenstates of Q.
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