Relativistic BCS-BEC Crossover at Finite Temperature and Its Application to Color Superconductivity

Understand

The non-relativistic $G_0 G$ formalism of BCS-BEC crossover at finite temperature is extended to relativistic fermion systems.

• The uncondensed pairs contribute a pseudogap to the fermion excitations.
• The theory recovers the BCS mean field approximation at zero temperature and the non-relativistic results in a proper limit.
• For massive fermions, when the coupling strength increases, there exist two crossovers from the weak coupling BCS superfluid to the non-relativistic BEC state and then to the relativistic BEC state.