We discuss some of the unusual characteristics of a Fermi superfluid formed by Cooper pairing in a system, such as spin-polarized 6Li, which possesses triple nuclear spin degeneracy. In particular we show (a) that the "naive" BCS expression for the transition temperature is (unlike in the usual spin-1/2 case) exact in the low-density limit, and (b) that there must always be a gapless branch of the excitation spectrum even for s-wave pairing, so that the normal density is nonzero at T = 0.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics