Zheng, ZhenQu, ChunleiZou, XuboZhang, Chuanwei2018-05-152018-05-152016-03-240031-9007http://hdl.handle.net/10735.1/5749Spin-imbalanced ultracold Fermi gases have been widely studied recently as a platform for exploring the long-sought Fulde-Ferrell-Larkin-Ovchinnikov superfluid phases, but so far conclusive evidence has not been found. Here we propose to realize an Fulde-Ferrell (FF) superfluid without spin imbalance in a three-dimensional fermionic cold atom optical lattice, where s- and p-orbital bands of the lattice are coupled by another weak moving optical lattice. Such coupling leads to a spin-independent asymmetric Fermi surface, which, together with the s-wave scattering interaction between two spins, yields an FF type of superfluid pairing. Unlike traditional schemes, our proposal does not rely on the spin imbalance (or an equivalent Zeeman field) to induce the Fermi surface mismatch and provides a completely new route for realizing FF superfluids.en©2016 American Physical Society. All Rights Reserved.Bose-Einstein condensationElectron gasSuperconductivitySuperfluidityOptical latticesFulde-Ferrell Superfluids without Spin Imbalance in Driven Optical LatticesarticleZheng, Zhen, Chunlei Qu, Xubo Zou, and Chuanwei Zhang. 2016. "Fulde-Ferrell Superfluids without Spin Imbalance in Driven Optical Lattices." Physical Review Letters 116(12), doi:10.1103/PhysRevLett.116.12040311612