Kohn Anomaly and Avoided Crossing (Anticrossing/Level Repulsion) are terms that are found to be used when discussing phonon dispersion. The former (see last paragraph, page 198) is related to electron-phonon coupling, while the latter (refer 2nd paragraph, page 55) is related to phonon-phonon coupling. Both phenomena lower the phonon frequency.

Are these concepts same, related or different?

  • $\begingroup$ I gave my +1 long ago, but I wonder if there's any update you can give us after all these months? Also, are you still actively in need of an answer to this question? $\endgroup$ Oct 12 at 15:31
  • $\begingroup$ Unfortunately I do not have any update, but for the sake of curiosity I would like to recieve the answer. $\endgroup$
    – AbPhys
    Oct 13 at 17:54
  • $\begingroup$ Thanks for the response AbPhys! If anyone has an answer, they're encouraged to ping me in a comment here, or to write a Flag asking for the question to be re-opened! $\endgroup$ Oct 13 at 20:03