What is fermi surface nesting? I don't have a hard reference, but I've heard this term thrown around quite a bit lately when talking about SDW, CDW, and SC.
nbo10 said:What is fermi surface nesting? I don't have a hard reference, but I've heard this term thrown around quite a bit lately when talking about SDW, CDW, and SC.
Fermi surface nesting and SDW, CDW interests physisists mainly of existence of phase transition to gap state in some direction.Can anyone elaborate on the connection between fermi surface nesting and SDW, CDW, etc. ? This has me kind-of puzzled too.
Generally, the Fermi liquid is very unstable because it has such a large density of states near the Fermi level.
Are you sure? Fermi liquid theory works so well because of its stability to perturbations. For generic momenta even four fermion interactions are irrelevant. Only the Cooper channel makes four fermion interactions marginal and hence we get superconductors. This is one of the very few instabilities of a Fermi liquid.
Nesting is another such instability. Density waves result from effective period doubling of the crystal lattice, which is a response of the Fermi liquid to avert the nesting instability.
The feeling I get from the gurus on this matter seems to be that serious work involving hard maths (algebraic geometry and the like) would be needed to start making dents on this issue...