Physics – Condensed Matter – Superconductivity
Scientific paper
2005-10-15
Nucl.Phys.B770:206-272,2007
Physics
Condensed Matter
Superconductivity
39 pages, 11 figures
Scientific paper
10.1016/j.nuclphysb.2007.02.026
We develop a functional integral formalism for ultracold gases of fermionic atoms. It describes the BEC - BCS crossover and involves both atom and molecule fields. Beyond mean field theory we include the fluctuations of the molecule field by the solution of gap equations. In the BEC limit, we find that the low temperature behavior is described by a Bogoliubov theory for bosons. For a narrow Feshbach resonance these bosons can be associated with microscopic molecules. In contrast, for a broad resonance the interaction between the atoms is approximately pointlike and microscopic molecules are irrelevant. The bosons represent now correlated atom pairs or composite ``dressed molecules''. The low temperature results agree with quantum Monte Carlo simulations. Our formalism can treat with general inhomogeneous situations in a trap. For not too strong inhomogeneities the detailed properties of the trap are not needed for the computation of the fluctuation effects - they enter only in the solutions of the field equations.
Diehl Sebastian
Wetterich Christof
No associations
LandOfFree
Functional Integral for Ultracold Fermionic Atoms does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Functional Integral for Ultracold Fermionic Atoms, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Functional Integral for Ultracold Fermionic Atoms will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-688512