Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Umklapp process

  1. Oct 30, 2013 #1
    This occur when two phonons interact and the sum of their momenta add to a new wavevector outside the new Brillioun zone. The resulting wavevector is then mapped back into the Brillioun zone by subtraction of a suitable reciprocal lattice vector.
    I don't think I understand the physics in all of this. I understand the idea but what is physically going on in this process and where does the leftover momentum go?
  2. jcsd
  3. Oct 30, 2013 #2


    User Avatar
    Science Advisor
    Gold Member

  4. Oct 31, 2013 #3


    User Avatar
    Science Advisor

    Well, of course also real momentum is conserved. It is taken up completely by the lattice.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook