Fermi Point - What is it? I'm trying to learn more about the idea of the quantum vacuum being a superfluid and how that can unify physics, but after all the reading I've done I can't quite nail down a conceptual understanding of the Fermi point of a superfluid. So, can someone explain to me what a Fermi point actually is in very simple terms?
I'm fascinated by the potential that this theory has as a GUT, and any help to further my understanding of the topic is greatly appreciated.
 A: As I understand it, a system has a Fermi point when a single point in momentum space lies at the Fermi energy. In most systems there is either a Fermi surface (conductor) or no Fermi surface (insulator/semi-conductor). The existence of a Fermi point has interesting implications, though I don't know much about it. From the forward by Volovik in 'The Universe in a Helium Droplet':
"The system is either fully gapped, or the Fermi surface is developed, or, what has most remarkable consequences, a singular point in the momentum space evolves - the Fermi point. If a Fermi point appears, as happens in superfluid $^3$He-A, at low energies the system is governed by a quantum field theory describing left-handed and right-handed fermionic quasiparticles interacting with effective gauge and gravity fields. Practically all the ingredients of the Standard Model emerge, together with Lorentz invariance and other physical laws. This suggests that maybe our quantum vacuum belongs to the same universality class ..."
A: Found this, you may have already read it but just noticed there were no answers. Sorry if this is not the answer you were looking for:

The fermi point is an amount of energy. Unless excited ,fermions will fill every state available that have energy less than or equal to the fermi point. Usually the Fermi level is used to discuss electrons in semiconductors and metals. In semiconductors at absolute zero, electrons will fill up every available state that have energy of less than or equal to the fermi point. At higher temperatures, some electrons will be excited, so there will be some electrons with energies above the fermi level. 

