title: Ultracold two-component fermionic gases with a magnetic field gradient near a feshbach resonance.
abstract: We study theoretically the ultracold two-component fermionic gases when a gradient magnetic field is used to tune the scattering length between atoms. For 6Li at the narrow resonance B0=543.25 G, it is shown that the gases would be in a coexistence of the regimes of BCS, Bose-Einstein condensation (BEC), and unitarity limit with the present experimental technique. In the case of thermal and chemical equilibrium, we investigate the density distribution of the gases and show that a double peak of the density distribution can give us a clear evidence for the coexistence of BCS, BEC, and unitarity limit.
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, Peoples Republic of China. xionghongwei@wipm.ac.cn
authors.forename: Hongwei
authors.initials: H
authors.lastname: Xiong
authors.forename: Shujuan
authors.initials: S
authors.lastname: Liu
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhang
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Zhan