Menu

Discussion Forum

New Discussion
Filter

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

phonon wave vector

Posted Sep 20, 2010, 1:25 p.m. EDT Structural Mechanics 6 Replies

Hussein Ayedh
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi everyone
it is the first time for me to work on comsol and I want to calculate the phonon modes in nanowire but I don't know how to extract the wave-vectors corresponding to the eigenfrequencies of the phonon modes . and how to export that to matlab. If someone knows about that ,please help me
6 Replies Last Post Jun 11, 2015, 2:18 a.m. EDT
COMSOL Moderator

Hello Hussein Ayedh

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Mike Bifano
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Oct 25, 2010, 2:11 p.m. EDT
Have you had any luck? I am interested in this as well.

Have you had any luck? I am interested in this as well.
Seid Mohamadali Sadat
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 12, 2012, 2:05 a.m. EDT
hi, could u find out how? I dont know how to define bloch boundary condition in solid mechanics physics.
hi, could u find out how? I dont know how to define bloch boundary condition in solid mechanics physics.
Nagi Elabbasi Facebook Reality Labs
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Apr 12, 2012, 10:28 p.m. EDT
You can manually define a Bloch boundary condition between two boundaries B1 and B2 by applying on boundary B1 a prescribed displacement of the form bndsim1(u)*exp(i*kx*L) where bndsim1() is a boundary similarity operator from Boundary B2. You should also specify that the displacement variables are complex and the Jacobian matrix is Hermetian.

Nagi Elabbasi
Veryst Engineering
You can manually define a Bloch boundary condition between two boundaries B1 and B2 by applying on boundary B1 a prescribed displacement of the form bndsim1(u)*exp(i*kx*L) where bndsim1() is a boundary similarity operator from Boundary B2. You should also specify that the displacement variables are complex and the Jacobian matrix is Hermetian. Nagi Elabbasi Veryst Engineering
Hyunjoon Park
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago May 5, 2015, 6:58 a.m. EDT
I am trying to solve nanowire`s phonon dispersion.

But I have trouble in solving it.

I used 2D axis & 3D circular design. But I can not get satisfied results..
(I used structure mechanics -> solid mechanics & periodic condition.)


I don`t have clue what is problem..
I am trying to solve nanowire`s phonon dispersion. But I have trouble in solving it. I used 2D axis & 3D circular design. But I can not get satisfied results.. (I used structure mechanics -> solid mechanics & periodic condition.) I don`t have clue what is problem..
Daniel Connelly
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago May 6, 2015, 12:28 p.m. EDT
How is a continuum model going to give optical phonon modes? Seems at best you can get only a linear approximation for low-k.
How is a continuum model going to give optical phonon modes? Seems at best you can get only a linear approximation for low-k.
Hyunjoon Park
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 10 years ago Jun 11, 2015, 2:18 a.m. EDT
I need to solve acoustic phonon modes & some lower optical modes.

If I use continuum model, I can not solve optical modes?

Could I know linear approximation setting method?
I need to solve acoustic phonon modes & some lower optical modes. If I use continuum model, I can not solve optical modes? Could I know linear approximation setting method?

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content