Route to observable Fulde-Ferrell-Larkin-Ovchinnikov phases in three-dimensional spin-orbit-coupled degenerate Fermi gases

摘要

The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase was first predicted in two-dimensional superconductorsnabout 50 years ago, but so far unambiguous experimental evidence is still lacking. The recently experimentallynrealized spin-imbalanced Fermi gases may potentially unveil this elusive state, but they require very stringentnexperimental conditions. In this Rapid Communication, we show that FFLO phases may be observed even in anthree-dimensional (3D) degenerate Fermi gas with spin-orbit coupling and an in-plane Zeeman field. The FFLOnphase is driven by the interplay between the asymmetry of the Fermi surface and the superfluid order, instead ofnthe interplay between magnetic and superconducting order in solid materials. The predicted FFLO phase existsnin a giant parameter region, possesses a stable long-range superfluid order due to the 3D geometry, and can benobserved with an experimentally already achieved temperature (T ∼ 0.05EF ), thus opening a fascinating avenuenfor exploring FFLO physics.