Experimental study of the BEC-BCS crossover region in lithium 6.
نویسندگان
چکیده
We report Bose-Einstein condensation of weakly bound 6Li2 molecules in a crossed optical trap near a Feshbach resonance. We measure a molecule-molecule scattering length of 170(+100)(-60) nm at 770 G, in good agreement with theory. We study the 2D expansion of the cloud and show deviation from hydrodynamic behavior in the BEC-BCS crossover region.
منابع مشابه
9 J an 2 00 7 Expansion of a lithium gas in the BEC - BCS crossover
— We present an experimental study of the time of flight properties of a gas of ultra-cold fermions in the BEC-BCS crossover. Since interactions can be tuned by changing the value of the magnetic field, we are able to probe both non interacting and strongly interacting behaviors. These measurements allow us to characterize the momentum distribution of the system as well as its equation of state...
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 کاملBroad versus narrow Fano - Feshbach resonances in the BCS - BEC crossover with trapped Fermi atoms
– With reference to the broad and narrow Fano-Feshbach resonances of 6 Li at about 822G and 543G, we show that for the broad resonance a molecular coupled-channel calculation can be mapped with excellent accuracy onto an effective single-channel problem with a contact interaction. This occurs for a wide enough range of the magnetic field, that the full BCS-BEC crossover can be realized with a t...
متن کاملExperimental realization of BCS-BEC crossover physics with a Fermi gas of atoms
This thesis presents experiments probing physics in the crossover between BoseEinstein condensation (BEC) and BCS superconductivity using an ultracold gas of atomic fermions. Scattering resonances in these ultracold gases (known as Feshbach resonances) provide the unique ability to tune the fermion-fermion interactions. The work presented here pioneered the use of fermionic Feshbach resonances ...
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 کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 93 5 شماره
صفحات -
تاریخ انتشار 2004