this is an important point regarding the HF mean-field theory, which basically emphasizes on the fact that mean-field parameter in HF is not a well-defined object and can change from problem to problem
Essentially, the major core of the “art” of mean-field is choosing a proper mean-field for the system at the given regime. That needs a lot of physical intuition and experience indeed, and it is very non-trivial.
NLU22 January 2018, 14:05 (UTC+00:00)
My perception from the Bruus's text is that HF mean field theory is just a procedure of decoupling and nothing more, like Hubbard-Stratonovich, which does not necessarily tells us about the proper mean field parameter. And that should be found through experience or intuition. This was not really clear to me before doing the HF mean field calculations in detail !.
https://imgur.com/fB60Ytw
this is an important point regarding the HF mean-field theory, which basically emphasizes on the fact that mean-field parameter in HF is not a well-defined object and can change from problem to problem
Frankie's post:
https://imgur.com/XSmxkM9
@Soroush: < https://imgur.com/fB60Ytw > is from Bruus and Flensberg.
@Frankie: < https://imgur.com/XSmxkM9 > is from Altland and Simons.
Essentially, the major core of the “art” of mean-field is choosing a proper mean-field for the system at the given regime. That needs a lot of physical intuition and experience indeed, and it is very non-trivial.
My perception from the Bruus's text is that HF mean field theory is just a procedure of decoupling and nothing more, like Hubbard-Stratonovich, which does not necessarily tells us about the proper mean field parameter. And that should be found through experience or intuition. This was not really clear to me before doing the HF mean field calculations in detail !.