This is a very common diagram of the superconducting density of states. In a normal metal, the Fermi energy lies somewhere in the conduction band and there are unoccupied states above it in the same band.
As we transition to the superconducting phase, the conduction electrons form Cooper pairs. I have read in various sources that the pairs "condense" into the same ground state. At absolute zero there are no conduction electrons left as they have all become Cooper pairs. At the same time an energy gap appears in the density of states, with $\Delta$ being several orders of magnitude below the energy range of the conduction band (I think).
My question is as follows: Where do the Cooper pairs fit in this diagram? What state to they occupy?
Do they all "condense" into the lowest energy state of the conduction band, and as pairs are broken do the electrons just populate the states in between the bottom of the band and the energy gap? Some sources state (unless I have misunderstood them) that when a Cooper pair breaks the electrons are excited above the energy gap. But what about all those states in the conduction band below the gap? Is this density of states even applicable to Cooper pairs, or will their ground state not even appear on this diagram? I would appreciate some help understanding this.