We study the effect of the induced interaction on the superfluid transition temperature of a spin-polarized Fermi gas. In the BCS limit, the polarization is very small in the superfluid state, and the effect of the induced interaction is almost the same as in the spin-balanced case. The temperature ${T}_{t}$ and the polarization ${P}_{t}$ of the tricritical point are both reduced from mean-field results by a factor about $2.22$ . This reduction is also significant beyond the BCS limit. In the unitary limit, we find $({P}_{t},{T}_{t}/{T}_{F})=(0.42,0.16)$ , in comparison with mean-field and experimental results.We study the effect of the induced interaction on the superfluid transition temperature of a spin-polarized Fermi gas. In the BCS limit, the polarization is very small in the superfluid state, and the effect of the induced interaction is almost the same as in the spin-balanced case. The temperature ${T}_{t}$ and the polarization ${P}_{t}$ of the tricritical point are both reduced from mean-field results by a factor about $2.22$. This reduction is also significant beyond the BCS limit. In the unitary limit, we find $({P}_{t},{T}_{t}/{T}_{F})=(0.42,0.16)$, in comparison with mean-field and experimental results.

Physical Review AJul 8, 201011 citations

Finite-temperature phase diagram of quasi-two-dimensional imbalanced Fermi gases beyond mean field

Maria Ângela de Araújo Resende, A. L. Mota, Ricardo L. S. Farias +1 more

We investigate the superfluid transition temperature of quasi-two-dimensional imbalanced Fermi gases beyond the mean-field approximation, through the second-order (or induced) interaction effects. For a balanced Fermi system the transition temperature is suppressed by a factor $\ensuremath{\approx}$ $2.72$ . For imbalanced Fermi systems, the polarization and transition temperature of the tricritical point are significantly reduced as the two-body binding energy $|{\ensuremath{\epsilon}}_{B}|$ increases.We investigate the superfluid transition temperature of quasi-two-dimensional imbalanced Fermi gases beyond the mean-field approximation, through the second-order (or induced) interaction effects. For a balanced Fermi system the transition temperature is suppressed by a factor $\ensuremath{\approx}$$2.72$. For imbalanced Fermi systems, the polarization and transition temperature of the tricritical point are significantly reduced as the two-body binding energy $|{\ensuremath{\epsilon}}_{B}|$ increases.

arXiv:1209.1838Physical Review ASep 4, 201215 citations

Induced interaction in a Fermi gas with a BEC-BCS crossover

Zeng-Qiang Yu, Kun Huang, Lan Yin

We study the effect of the induced interaction on the superfluid transition temperature of a Fermi gas with a Bose-Einstein condensation--Bardeen-Cooper-Schrieffer (BEC-BCS) crossover. The Gorkov-Melik-Barkhudarov theory about the induced interaction is extended from the BCS side to the entire crossover and the pairing fluctuation is treated in the approach by Nozi\`eres and Schmitt-Rink. At unitarity, the induced interaction reduces the transition temperature by about 20%. In the BCS limit, the transition temperature is reduced by a factor of about 2.22, as found by Gorkov and Melik-Barkhudarov. Our result shows that the effect of the induced interaction is important both on the BCS side and in the unitary region.We study the effect of the induced interaction on the superfluid transition temperature of a Fermi gas with a Bose-Einstein condensation--Bardeen-Cooper-Schrieffer (BEC-BCS) crossover. The Gorkov-Melik-Barkhudarov theory about the induced interaction is extended from the BCS side to the entire crossover and the pairing fluctuation is treated in the approach by Nozi\`eres and Schmitt-Rink. At unitarity, the induced interaction reduces the transition temperature by about 20%. In the BCS limit, the transition temperature is reduced by a factor of about 2.22, as found by Gorkov and Melik-Barkhudarov. Our result shows that the effect of the induced interaction is important both on the BCS side and in the unitary region.

arXiv:0905.1023Physical Review AMay 22, 200937 citations

Induced p -wave superfluidity in strongly interacting imbalanced Fermi gases

Kelly R. Patton, Daniel E. Sheehy

The induced interaction among the majority spin species, due to the presence of the minority species, is computed for the case of a population-imbalanced resonantly interacting Fermi gas. It is shown that this interaction leads to an instability, at low temperatures, of the recently observed polaron Fermi liquid phase of strongly imbalanced Fermi gases to a $p$ -wave superfluid state. We find that the associated transition temperature, while quite small in the weakly interacting BCS regime, is experimentally accessible in the strongly interacting unitary regime.The induced interaction among the majority spin species, due to the presence of the minority species, is computed for the case of a population-imbalanced resonantly interacting Fermi gas. It is shown that this interaction leads to an instability, at low temperatures, of the recently observed polaron Fermi liquid phase of strongly imbalanced Fermi gases to a $p$-wave superfluid state. We find that the associated transition temperature, while quite small in the weakly interacting BCS regime, is experimentally accessible in the strongly interacting unitary regime.

arXiv:1011.4536Physical Review AMay 31, 201117 citations

Influence of induced interactions on superfluid properties of quasi-two-dimensional dilute Fermi gases with spin-orbit coupling

Heron Caldas, Ricardo L. S. Farias, M. A. Contínentino

We study the effects of induced interactions on the pairing gap, transition temperature, and chemical potential of a quasi-two-dimensional Fermi gas of atoms with spin-orbit coupling. We find that these mean-field parameters are significantly modified when induced interactions are taken into account. We also investigate the implications of induced interaction corrections for the BEC-BCS crossover driven by spin-orbit coupling, which happens even for small (compared to the Fermi energy) values of the binding energy.We study the effects of induced interactions on the pairing gap, transition temperature, and chemical potential of a quasi-two-dimensional Fermi gas of atoms with spin-orbit coupling. We find that these mean-field parameters are significantly modified when induced interactions are taken into account. We also investigate the implications of induced interaction corrections for the BEC-BCS crossover driven by spin-orbit coupling, which happens even for small (compared to the Fermi energy) values of the binding energy.

arXiv:1512.03964Physical Review AAug 26, 20137 citations

Fluctuation corrections to the mean-field interaction for a trapped Fermi gas

Jin Woo Jun

Assuming that the scattering length properly describes the interaction, and taking into account the lowest-order correction effects to the strong mean-field interaction, we find that the density distributions of a Fermi gas in each spin state do not change significantly under the BCS transition, but the critical temperature is reduced significantly in comparison with the case without the fluctuation effect. The inclusion of the fluctuation correction effect for a large value of scattering length affects the expansion of a Fermi gas only in a minor way The expansion of a Fermi gas depends in a crucial way on whether the system is in the collisionless regime or in the hydrodynamic regime.Assuming that the scattering length properly describes the interaction, and taking into account the lowest-order correction effects to the strong mean-field interaction, we find that the density distributions of a Fermi gas in each spin state do not change significantly under the BCS transition, but the critical temperature is reduced significantly in comparison with the case without the fluctuation effect. The inclusion of the fluctuation correction effect for a large value of scattering length affects the expansion of a Fermi gas only in a minor way The expansion of a Fermi gas depends in a crucial way on whether the system is in the collisionless regime or in the hydrodynamic regime.

Physical Review AApr 17, 20032 citations

{T}_{t}

and the polarization

{P}_{t}

of the tricritical point are both reduced from mean-field results by a factor about

2.22

. This reduction is also significant beyond the BCS limit. In the unitary limit, we find

({P}_{t},{T}_{t}/{T}_{F})=(0.42,0.16)

, in comparison with mean-field and experimental results.

2.72

. For imbalanced Fermi systems, the polarization and transition temperature of the tricritical point are significantly reduced as the two-body binding energy $|{\ensuremath{\epsilon}}_{B}|$ increases.

p

-wave superfluid state. We find that the associated transition temperature, while quite small in the weakly interacting BCS regime, is experimentally accessible in the strongly interacting unitary regime.