What does a horizontal band in the Phonon band structure mean?

[asgharali_jan]

if i have a horzental straight band in phonon despersion what does that means? whats physics behind that band?

[michael_wolloch]

Dear asgharali_jan,

since this post is not directly related to the usage of VASP, I moved it to the "From users for users" section of the forum.

Flat bands can signify interesting physics. I want to give the discussions by the users a jump start by linking two papers:

Phys. stat. sol. (c) 1, No. 11, 3043–3046 (2004) discusses the construction of flat phonon bands in a 2D lattice by tuning the force constant matrix.

Science 369, 1343-1347 (2020) discusses ferroelectricity in HfO2 induced by flat phonon bands.

Cheers, Michael

[asgharali_jan]

thanks a lot for information