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Density matrix doubt

  1. Jun 25, 2009 #1
    In a density matrix, can some coherances (off diagonal terms) be zero while the diagonal terms(populations) aren't? I am confused because rhoij=Ci*Cj'. How can coherance be zero if Ci and Cj aren't?
  2. jcsd
  3. Jun 25, 2009 #2


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    Yse, coherences can be zero. If you're at equilibrium, they're all zero.
  4. Jun 25, 2009 #3


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    Your density matrix applies to a "pure state" only. Look up "pure states" and "mixed states".
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