Achieving a BCS Transition in an Atomic Fermi Gas
Abstract
We consider a gas of cold fermionic atoms having two spin components with interactions characterized by their swave scattering length a. At positive scattering length the atoms form weakly bound bosonic molecules which can be evaporatively cooled to undergo BoseEinstein condensation, whereas at negative scattering length BCS pairing can take place. It is shown that, by adiabatically tuning the scattering length a from positive to negative values, one may transform the molecular BoseEinstein condensate into a highly degenerate atomic Fermi gas, with the ratio of temperature to Fermi temperature T/T_{F}∼10^{2}. The corresponding critical final value of k_{F}a, which leads to the BCS transition, is found to be about onehalf, where k_{F} is the Fermi momentum.
 Publication:

Physical Review Letters
 Pub Date:
 April 2004
 DOI:
 10.1103/PhysRevLett.92.150404
 arXiv:
 arXiv:condmat/0308306
 Bibcode:
 2004PhRvL..92o0404C
 Keywords:

 03.75.Ss;
 05.30.Fk;
 36.90.+f;
 67.40.Db;
 Degenerate Fermi gases;
 Fermion systems and electron gas;
 Other exotic atoms and molecules;
 macromolecules;
 clusters;
 Quantum statistical theory;
 ground state elementary excitations;
 Condensed Matter  Superconductivity
 EPrint:
 4 pages, 1 figure. Phys. Rev. Lett. in press