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Change of basis

  1. Mar 4, 2004 #1
    Hello all,

    I need some help...
    If I know the form of a wavefunction in the [itex] S_z [/itex] basis, say it is spin up, how do I convert that to a wavefunction expressed in the [itex] S_x [/itex] basis? Is there a very simple way to do this?
  2. jcsd
  3. Mar 5, 2004 #2
    Do I just rotate the spinor using a rotation operator?
  4. Mar 5, 2004 #3

    Tom Mattson

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    You've basically got it. To convert from Sz to Sx, you rotate the state vector p/2 rad about the y-axis.
  5. Sep 27, 2011 #4
    Hi, I know this is old. Im sorry, but I have some confusion about this.

    I wonder, shouldn't the new state vector be a superposition of +x and -x? If I apply the rotation operator to my z state I get a pure state.

    Where has my thinking gone wrong?
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