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Homework Help: Spin wave dispertion finite energy.

  1. May 29, 2006 #1
    Hi there,

    I've been trying to explain why at zero wave vector Q , in some ferromagnetic materials the spin wave has a finite energy. I know that usually the energy tends to zero as the wave vector tends to zero however in some cases there is energy at zero, wave vector, I just need to know why.

    I would appreciate someone to enlighten me

    newo
     
  2. jcsd
  3. May 29, 2006 #2

    Gokul43201

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    Most all real ferromagnetic materials have a non-zero (typically about an meV or less) spin-wave energy at q=0 that comes from the anisotropy field. Kittel has a paper on this. I'll look for it if you confirm that this is what you are talking about.

    If you are talking about a larger minimum energy in some special materials, I'm unaware of that.
     
  4. May 30, 2006 #3
    yes that is what i am looking for thank you, i would be greatful if i can see the paper.
     
  5. May 30, 2006 #4

    Gokul43201

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