Have I got this right?

[dimreepr]

The fermionic condensate is made of matter and the BEC is made of photons and gluons? Does this mean that the BEC is a liquid force field (or maybe a superliquid force field)?

 

 

[timo]

The Bose-Einstein condensate (BEC) consists of bosonic particles. That can in fact also encompass matter. Typically, one uses certain atoms for realizing a BEC. Wikipedia says in this context that

In 1995 the first gaseous condensate was produced by Eric Cornell and Carl Wieman at the University of Colorado at Boulder NIST–JILA lab, using a gas of rubidium atoms cooled to 170 nanokelvin (nK) [5] (1.7×10−7 K). For their achievements Cornell, Wieman, and Wolfgang Ketterle at MIT received the 2001 Nobel Prize in Physics.[6] In November 2010 the first photon BEC was observed

So according to above, photons have also been used (though that does sound way less impressive to me, at least at first). Gluons would be problematic: The theory of BECs does not consider a possible interaction between the particles forming the condensate, whereas gluons interact strongly.

Edited July 2, 2012 by timo

[MigL]

It is my understanding that half-integer spin fermions acting in pairs can imitate integer spin bosons. Superconductivity theory is based on this effect. I would think BEC can consist of paired fermions.

[imatfaal]

Cooper pairs

 

http://en.m.wikipedia.org/wiki/Cooper_pair

 

Electrons have spin-1⁄2, so they are fermions, but a Cooper pair is a composite boson as its total spin is integer (0 or 1). This means the wave functions are symmetric under particle interchange, and they are allowed to be in the same state. The tendency for all the Cooper pairs in a body to 'condense' into the same ground quantum state is responsible for the peculiar properties of superconductivity

[Enthalpy]

I seriously hope that both the Cooper pair and the BCS theories offer better explanations than the usual "pairs of fermions are bosons so they occupy the same state", which is an absolute nonsense.

 

ONE pair of fermions can occupy a state and that's all. This is what happens in any molecule, where electrons are paired with opposite spins, and each orbital is full with a pair of electrons.