BCS-BEC crossover
= BCS-BEC crossover
{c}
The continuous evolution, in suitable attractive Fermi systems, from weakly paired overlapping <Cooper pairs> to tightly bound composite <bosons> undergoing <Bose-Einstein condensation>. Pair formation, phase coherence and the <chemical potential> must be determined consistently across the crossover. A weak-coupling gap-temperature formula with fixed <density of states> is not uniformly valid through the molecular limit.