We consider a two-component Fermi gas interacting via a Feshbach molecular state. It is shown that only for broad resonances where the Feshbach state is strongly coupled to the free particle continuum can the gas be expected to enter a universal state in the unitarity limit on the atomic side of the resonance where there are no molecules present. The universal state is distinct from the molecular gas state on the other side of the resonance. We furthermore calculate the energy of the gas for this universal state and our results are related to current experiments on $^{6}\mathrm{Li}$ and $^{40}\mathrm{K}$ .We consider a two-component Fermi gas interacting via a Feshbach molecular state. It is shown that only for broad resonances where the Feshbach state is strongly coupled to the free particle continuum can the gas be expected to enter a universal state in the unitarity limit on the atomic side of the resonance where there are no molecules present. The universal state is distinct from the molecular gas state on the other side of the resonance. We furthermore calculate the energy of the gas for this universal state and our results are related to current experiments on $^{6}\mathrm{Li}$ and $^{40}\mathrm{K}$.

arXiv:cond-mat/0401497Physical Review ANov 4, 200447 citations

Studies of a single component Fermi gas near a p-wave resonance with the lowest order constrained variational method

Guangcun Liu, Yi-Cai Zhang

We study a single component Fermi gas near a p -wave resonance with the lowest order constrained variational (LOCV) method. We obtain the energy per particle for the ground state of the single component Fermi gas near a p -wave resonance with the LOCV method. We also calculate the compressibility of the single component Fermi gas near a p -wave resonance and it shows that in the strongly interacting BCS side, the system would lose its stability and collapse. The width of the unstable region is proportional to the Fermi energy which reflects the universality of the dilute Fermi gas. The two p -wave contacts are also obtained and their variation tendencies with the interaction strength are qualitatively in agreement with recent experimental results.We study a single component Fermi gas near a p -wave resonance with the lowest order constrained variational (LOCV) method. We obtain the energy per particle for the ground state of the single component Fermi gas near a p -wave resonance with the LOCV method. We also calculate the compressibility of the single component Fermi gas near a p -wave resonance and it shows that in the strongly interacting BCS side, the system would lose its stability and collapse. The width of the unstable region is proportional to the Fermi energy which reflects the universality of the dilute Fermi gas. The two p -wave contacts are also obtained and their variation tendencies with the interaction strength are qualitatively in agreement with recent experimental results.

arXiv:1710.06581Europhysics Letters (EPL)Jul 2, 20185 citations

^{6}\mathrm{Li}

and

^{40}\mathrm{K}