BCS-BEC crossover at finite temperature for superfluid trapped Fermi atoms.
نویسندگان
چکیده
We consider the BCS-BEC (Bose-Einstein-condensate) crossover for a system of trapped Fermi atoms at finite temperature, both below and above the superfluid critical temperature, by including fluctuations beyond mean field. We determine the superfluid critical temperature and the pair-breaking temperature as functions of the attractive interaction between Fermi atoms, from the weak- to the strong-coupling limit (where bosonic molecules form as bound-fermion pairs). Density profiles in the trap are also obtained for all temperatures and couplings.
منابع مشابه
Superfluid transition temperature in a trapped gas of Fermi atoms with a Feshbach resonance
We investigate strong coupling effects on the superfluid phase transition in a gas of Fermi atoms with a Feshbach resonance. The Feshbach resonance describes a composite quasi-Boson, which can give rise to an additional pair-ing interaction between the Fermi atoms. This attractive interaction becomes stronger as the threshold energy (2ν) of the Feshbach resonance two-particle bound state is low...
متن کاملExtracting the condensate density from projection experiments with Fermi gases.
A debated issue in the physics of the BCS-BEC crossover with trapped Fermi atoms is to identify characteristic properties of the superfluid phase. Recently, a condensate fraction was measured on the BCS side of the crossover by sweeping the system in a fast (nonadiabatic) way from the BCS to the Bose-Einstein condensation (BEC) sides, thus "projecting" the initial many-body state onto a molecul...
متن کاملS ep 2 00 6 Mean - Field vs Monte - Carlo equation of state for the expansion of a Fermi superfluid in the BCS - BEC crossover
The equation of state (EOS) of a Fermi superfluid is investigated in the BCS-BEC crossover at zero temperature. We discuss the EOS based on Monte-Carlo (MC) data and asymptotic expansions and the EOS derived from the extended BCS (EBCS) mean-field theory. Then we introduce a time-dependent density functional, based on the bulk EOS and Landau’s superfluid hydrodynamics with a von Weizsäcker-type...
متن کاملBCS-BEC crossover in an asymmetric two-component Fermi gas
– We discuss the superfluid phase transition of a strongly interacting Fermi gas with unequal (asymmetric) chemical potentials in two pairing hyperfine states, and map out its phase diagram near the BCS-BEC crossover. Our approach includes the fluctuation contributions of “preformed Cooper pairs” to the thermodynamic potential at finite temperature. We show that, below a critical difference in ...
متن کاملEquation of state of a superfluid Fermi gas in the BCS - BEC crossover
– We present a theory for a superfluid Fermi gas near the BCS-BEC crossover, including pairing fluctuation contributions to the free energy similar to that considered by Nozì eres and Schmitt-Rink for the normal phase. In the strong coupling limit, our theory is able to recover the Bogoliubov theory of a weakly interacting Bose gas with a molecular scattering length very close to the known exac...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 92 22 شماره
صفحات -
تاریخ انتشار 2004