2006/07/31 by Daniel E. Sheehy, Leo Radzihovsky · 8 citations
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Cooper pair #Degenerate energy levels #Diatomic molecule #Fermi Gamma-ray Space Telescope #Fermi gas #Phase (matter) #Phase transition #Physics of Superconductivity and Magnetism #Strong Light-Matter Interactions #Superfluidity #cond-mat.supr-con
paper · pdf · doi:10.1016/j.aop.2006.09.009
published as Annals of Physics 322, 1790 (2007) · 76 RevTeX pages, 54 figures. Corrected typos. PRB two-column format. To appear in Annals of Physics (already available online at AOP website)
openalex publication_date 2006/11/22 · arxiv created 2007/01/23 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study resonantly-paired s-wave superfluidity in a degenerate gas of two species (hyperfine states labeled by \uparrow,\downarrow) of fermionic atoms when the numbers N\uparrow and N\downarrow of the two species are \it unequal, i.e., the system is "polarized". We find that the continuous crossover from the Bose-Einstein condensate (BEC) limit of tightly-bound diatomic molecules to the Bardeen-Cooper-Schrieffer (BCS) limit of weakly correlated Cooper pairs, studied extensively at equal populations, is interrupted by a variety of distinct phenomena under an imposed population difference ΔN ≡ N_\uparrow - N_\downarrow. Our findings are summarized by a `` polarization\rq\rq (ΔN) versus Feshbach-resonance detuning (δ) zero-temperature phase diagram, which exhibits regions of phase separation, a periodic FFLO superfluid, a polarized normal Fermi gas and a polarized molecular superfluid consisting of a molecular condensate and a fully polarized Fermi gas. We describe numerous experimental signatures of such phases and the transitions between them, in particular focusing on their spatial structure in the inhomogeneous environment of an atomic trap.