Lee-Yang cluster expansion approach to the BCS-BEC crossover: BCS and BEC limits
arXiv:1310.4665 · doi:10.1103/PhysRevA.89.033622
Abstract
It is shown that a cluster expansion technique, which is usually applied in the high-temperature regime to calcutate virial coefficients, can be applied to evaluate the superfluid transition temperature of the BCS-BEC crossover à la Lee and Yang. The transition temperature is identified with the emergence of the singularity in the sum of a certain infinite series of cluster functions. In the weak-coupling limit, we reproduce the Thouless criterion and the number equation of Nozières and Schmitt-Rink, and hence the transition temperature of the BCS theory. In the strong-coupling limit, we reproduce the transition temperature of Bose-Einstein condensation of non-interacting tightly bound dimers.
18 pages, 6 figures; Subsec. III-D and Figs.4 and 6 added; to appear in Physical Review A
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Cited by in corpus (4)
- Third virial coefficient of the unitary Bose gas
- Universal relations for spin-orbit-coupled Fermi gases in two and three dimensions
- Effective Hamiltonian based Monte Carlo for the BCS to BEC crossover in the attractive Hubbard model
- Toward an automated-algebra framework for high orders in the virial expansion of quantum matter