1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How can we find the variance of S_x, S_y, and S_z?

  1. Dec 5, 2007 #1
    Given |Psi> = a|up>+b|down>, in principle it should not be so difficult but when I calculate

    Delta S=Sqrt[<S^2_x,S^2_y, or S^2_z>-<S_x,S_y, or S_z>^2]

    the second term gives the problem. Lots of many terms a*, a, b*, b which is not cancelled involve.

    Whoever knows the way to get rid of this problem, please let me know.
     
  2. jcsd
  3. Dec 6, 2007 #2

    Galileo

    User Avatar
    Science Advisor
    Homework Helper

    Can you show what you've tried so far?
    For example, how did you go about finding <S_x>?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?