Qj. Chen et al., Unusual thermodynamical and transport signatures of the BCS to Bose-Einstein crossover scenario below T-c, PHYS REV L, 85(13), 2000, pp. 2801-2804
In this paper we present predictions for thermodynamic and transport proper
ties of a BCS to Bose-Einstein crossover theory, below T-c, which satisfies
the reasonable constraints that it yields (i) the Leggett ground state and
(ii) BCS theory at weak coupling and all temperatures T. The nature of the
strong coupling limit is inferred, along with the behavior of the Knight s
hift, superfluid density, and specific heat. Comparisons with existing data
on short coherence length superconductors, such as organic and high T-c sy
stems, are presented, which provide some support for the present picture.