- #1
siddharth5129
- 94
- 3
I've been reading Kittel's book on Solid state physics and while it's been mostly smooth sailing, the abrupt loss of rigour in places in unsettling. In particular, the bits about scattering seem to be just thrown in here and there without any rigourous mathematical treatment at all.
He talks about electron-phonon , phonon-phonon, and x ray - phonon scattering processes. What exactly are the mechanisms behind these processes. How and why does this kind of scattering occur. Further, how does phonon and electron scattering off a lattice imperfection occur? Surely, there must be some kind of theory behind scattering which makes all this rigourous.
Secondly, he says that phonon-phonon scattering processes can only occur by an anharmonic interaction. I'm not sure if I've understood this. What exactly does this mean ?
An lastly, Umklapp scattering. I get how the mathematics behind the whole things works out, but if you're claiming that momentum isn't conserved in a certain process, shouldn't you identify the force in play that makes it happen? Shouldn't there be some kind of 'recoil' or 'force' associated with the addition of a reciprocal lattice vector G. The book I'm using doesn't identify any such 'force' or 'recoil'.
Thanks for all the help. Greatly appreciated. :)
He talks about electron-phonon , phonon-phonon, and x ray - phonon scattering processes. What exactly are the mechanisms behind these processes. How and why does this kind of scattering occur. Further, how does phonon and electron scattering off a lattice imperfection occur? Surely, there must be some kind of theory behind scattering which makes all this rigourous.
Secondly, he says that phonon-phonon scattering processes can only occur by an anharmonic interaction. I'm not sure if I've understood this. What exactly does this mean ?
An lastly, Umklapp scattering. I get how the mathematics behind the whole things works out, but if you're claiming that momentum isn't conserved in a certain process, shouldn't you identify the force in play that makes it happen? Shouldn't there be some kind of 'recoil' or 'force' associated with the addition of a reciprocal lattice vector G. The book I'm using doesn't identify any such 'force' or 'recoil'.
Thanks for all the help. Greatly appreciated. :)