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Homework Help: Van Leeuwen's theorem

  1. Apr 3, 2006 #1
    For a statistical mechanics course we have to prove Van Leeuwen's theorem: Diamagnetism does not exist in classical physics.

    I know that in an external magnetic field H the Hamiltonian Ha goes from Ha(p1,p2,--------,pN ,q1,q2,-------qN) to Ha(p1-(e/c)A1, p2-(e/c)A2, ------- pN-(e/c)AN, q1,q2,------.qN)

    I also know that the induced magnetization M = kT*d(log QN)/dH

    So the problem is finding QN. I know how to calculate it for a perfect gas without the magnetic field but I can't seem to solve the integral when Ha changes.
  2. jcsd
  3. Apr 3, 2006 #2

    Physics Monkey

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    Try shifting integration variables.
  4. Apr 4, 2006 #3
    Ah I found bij changing p - (e/c)A to p' and then integrating. Thanks a lot.
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