Can bosonic and fermionic condensates explain superfluid and superconducting properties? Are they better than the theory of BCS and Landau?


My question is based in this lecture pesentation From BEC to CBS. In particular in this slide:

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    $\begingroup$ "Bosonic and fermionic condensates" is not a theory. Until you actually have a theory, your question isn't really answerable. What's more, BCS theory already involves fermionic condensates. $\endgroup$ Oct 16, 2017 at 19:29
  • $\begingroup$ @Chris please, check out my edit. $\endgroup$ Oct 16, 2017 at 19:50
  • $\begingroup$ I still don't understand your question. What two things are you trying to compare? BCS and Landaus theory of super-fluidity are how you describe weak coupling condensates. " bosonic and fermionic condensates" are things with superfluid or superconducting properties (zero viscosity, quantized vortices...) not theories themselves. $\endgroup$ Oct 17, 2017 at 0:25
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    $\begingroup$ Superfluidity in He^4 is more or less a Bose-Einstein condensate, in He^3 it comes from Cooper pairing of fermions to form a quasi Bose-Einstein condensate. The second order phase transition is responsible for the phenomenology of the superfluid state. A superconductor is a pseudo Bose-Einstein condensate made on top of the Cooper instability in the Fermi gas (also called a metal, this later being described by the Landau theory of the Fermi liquid). The superconducting phenomenology is explained by a Anderson-Higgs phenomenon (the electromagnetic gauge redundancy goes to a smaller group). $\endgroup$
    – FraSchelle
    Oct 17, 2017 at 7:38
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    $\begingroup$ The Anderson-Higgs phenomenon is encapsulated in the Bardeen-Cooper-Schriffer (BCS) model, as it is in the Ginzburg-Landau formalism. BCS theory is considered as the sufficient model to describe first generation superconductors (before the 80's, say). It's based on a mean-field approximation of an effective theory of the electron-phonon coupling in a Fermi liquid. Ginzburg-Landau functional describes all the electromagnetic properties of a superconductor. $\endgroup$
    – FraSchelle
    Oct 17, 2017 at 7:42


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