Effect Of Induced Interaction Research Articles

The Gor'kov and Melik‐Barkhudarov Correction to an Imbalanced Fermi Gas in the Presence of Impurities

AbstractThe effects of induced interactions are calculated in both clean and dirty situations, for balanced and imbalanced Fermi gases. The effects of nonmagnetic impurities on the induced interactions corrections to the transition temperature in the case of a balanced gas, and to the tricritical point in the case of an imbalanced Fermi gas at unitarity are investigated. It is found that impurities act in detriment of the induced interactions, or particle–hole fluctuations, for the transition temperature and the tricritical point. For large impurity parameter, the particle–hole fluctuations are strongly suppressed. The Chandrasekhar–Clogston limit of an imbalanced Fermi gas at unitarity considering the effects of the induced interactions, both in the pure and impurity regimes have also been found.

The Gor'kov and Melik‐Barkhudarov Correction to the Mean‐Field Critical Field Transition to Fulde–Ferrell–Larkin–Ovchinnikov States

AbstractThe Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) states, characterized by Cooper pairs condensed at finite‐momentum are, at the same time, exotic and elusive. It is partially due to the fact that the FFLO states allow superconductivity to survive even in strong magnetic fields at the mean‐field level. The effects of induced interactions at zero temperature are calculated in both clean and dirty cases, and it is found that the critical field at which the quantum phase transition to an FFLO state occurs at the mean‐field level is strongly suppressed in imbalanced Fermi gases. This strongly shrinks the phase space region where the FFLO state is unstable and more exotic ground state is to be found. In the presence of high level impurities, this shrinkage may destroy the FFLO state completely.

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

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 interactions corrections for the BCS-BEC crossover driven by spin-orbit coupling, that happens even for small (compared to the Fermi energy) values of the binding energy.