Evidence for Superfluidity of Ultracold Fermions in an Optical Lattice

Abstract

The study of superfluid fermion pairs in a periodic potential has important ramifications for understanding superconductivity in crystalline materials. Using cold atomic gases, various condensed matter models can be studied in a highly controllable environment. Weakly repulsive fermions in an optical lattice could undergo d-wave pairing at low temperatures, a possible mechanism for high temperature superconductivity in the cuprates. The lattice potential could also strongly increase the critical temperature for s-wave superfluidity. Recent experimental advances in the bulk include the observation of fermion pair condensates and high-temperature superfluidity. Experiments with fermions and bosonic bound pairs in optical lattices have been reported, but have not yet addressed superfluid behavior. Here we show that when a condensate of fermionic atom pairs was released from an optical lattice, distinct interference peaks appear, implying long range order, a property of a superfluid. Conceptually, this implies that strong s-wave pairing and superfluidity have now been established in a lattice potential, where the transport of atoms occurs by quantum mechanical tunneling and not by simple propagation. These observations were made for unitarity limited interactions on both sides of a Feshbach resonance. For larger lattice depths, the coherence was lost in a reversible manner, possibly due to a superfluid to insulator transition. Such strongly interacting fermions in an optical lattice can be used to study a new class of Hamiltonians with interband and atom-molecule couplings.

accepted for publication in Nature

References in corpus (9)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Observation of Bose-Einstein Condensation of Molecules
• Repulsively bound atom pairs in an optical lattice
• Molecules of Fermionic Atoms in an Optical Lattice
• Preparation of a quantum state with one molecule at each site of an optical lattice
• Superfluid Expansion of a Strongly Interacting Fermi Gas
• Multiple species atom source for laser-cooling experiments
• Dressed molecules in an optical lattice

Cited by in corpus (105)

• Theory of ultracold Fermi gases
• Non-Abelian Topological Order in S-Wave Superfluids of Ultracold Fermionic Atoms
• A Quantum Gas Microscope for Fermionic Atoms
• Non-Abelian Topological Orders and Majorana Fermions in Spin-Singlet Superconductors
• Monte Carlo study of two-dimensional Bose-Hubbard model
• Color Superfluidity and "Baryon" Formation in Ultracold Fermions
• State preparation and dynamics of ultracold atoms in higher lattice orbitals
• Species-specific optical lattices
• Critical velocity for superfluid flow across the BEC-BCS crossover
• Antiferromagnetic Order of Strongly Interacting Fermions in a Trap: Real-Space Dynamical Mean-Field Analysis
• Interaction-controlled transport of an ultracold Fermi gas
• Measuring the one-particle excitations of ultracold fermionic atoms by stimulated Raman spectroscopy
• Finite temperature phase diagram of a polarized Fermi gas in an optical lattice
• Localization-Delocalization Transition of Indirect Excitons in Lateral Electrostatic Lattices
• Dissipation-induced d-Wave Pairing of Fermionic Atoms in an Optical Lattice
• Direct observation of non-local fermion pairing in an attractive Fermi-Hubbard gas
• Superfluidity at the BEC-BCS crossover in two-dimensional Fermi gases with population and mass imbalance
• When Superconductivity Crosses Over: From BCS to BEC
• Dynamical mean-field theory and numerical renormalization group study of superconductivity in the attractive Hubbard model
• Level crossing in the three-body problem for strongly interacting fermions in a harmonic trap
• Superfluid-Insulator Transition of Strongly Interacting Fermi Gases in Optical Lattices
• Berezinskii-Kosterlitz-Thouless transition in trapped quasi-two-dimensional Fermi gas near a Feshbach resonance
• Spectral signatures of the Fulde-Ferrell-Larkin-Ovchinnikov order parameter in one-dimensional optical lattices
• Renormalization group flow for fermionic superfluids at zero temperature
• The effect of population imbalance on the Berezinskii-Kosterlitz-Thouless phase transition in a superfluid Fermi gas
• Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas
• Superfluid Fermi atomic gas as a quantum simulator for the study of neutron-star equation of state
• Stable Fulde-Ferrell-Larkin-Ovchinnikov pairing states in 2D and 3D optical lattices
• Superconductivity in the attractive Hubbard model: functional renormalization group analysis
• Light scattering for thermometry of fermionic atoms in an optical lattice
• Magnetism and domain formation in SU(3)-symmetric multi-species Fermi mixtures
• Superfluid to normal phase transition in strongly correlated bosons in two and three dimensions
• Supersolid state of ultracold fermions in an optical lattice
• BCS-BEC Crossover of a Quasi-two-dimensional Fermi Gas: the Significance of Dressed Molecules
• Imbalanced Fermi superfluid in a one-dimensional optical potential
• General Hubbard model for strongly interacting fermions in an optical lattice and its phase detection
• Superfluid and insulating phases of fermion mixtures in optical lattices
• Magnetism, coherent many-particle dynamics, and relaxation with ultracold bosons in optical superlattices
• Three-Component Fermionic Atoms with Repulsive Interaction in Optical Lattices
• Quantum Hall-like effect for cold atoms in non-Abelian gauge potentials
• Rice-Mele model with topological solitons in an optical lattice
• Supersolid state in fermionic optical lattice systems
• Supersolids in confined fermions on one-dimensional optical lattices
• Magnetic and superfluid phases of confined fermions in two-dimensional optical lattices
• Characteristics of Bose-Einstein condensation in an optical lattice
• Molecular Bose-Einstein condensation in a versatile low power crossed dipole trap
• Stability of Superflow for Ultracold Fermions in Optical Lattices
• Electron coherent and incoherent pairing instabilities in inhomogeneous bipartite and nonbipartite nanoclusters
• Induced interactions for ultracold Fermi gases in optical lattices
• Antiferromagnetic noise correlations in optical lattices
• Effective low-dimensional Hamiltonian for strongly interacting atoms in a transverse trap
• Resonant enhancement of the FFLO-state in 3D by a one-dimensional optical potential
• Population imbalanced fermions in harmonically trapped optical lattices
• Quantum phases of Fermi-Fermi mixtures in optical lattices
• Engineered Open Systems and Quantum Simulations with Atoms and Ions
• Commensurability effects for fermionic atoms trapped in 1D optical lattices
• Cold Fermionic Atoms in Two-Dimensional Traps -- Pairing versus Hund's Rule
• Reentrant BCS-BEC crossover and a superfluid-insulator transition in optical lattices
• Noise correlations of the ultra-cold Fermi gas in an optical lattice
• Competing Superconducting States for Ultracold Atoms in Optical Lattices with Artificial Staggered Magnetic Field
• Ultracold Feshbach molecules in an orbital optical lattice
• Correlation Effects on Atom Density Profiles of 1-D and 2-D Polarized Atomic-Fermi-Gas Loaded on Optical Lattice
• Quantum critical dynamics in a spinor Hubbard model quantum simulator
• Spatial patterns in optical lattices submitted to gauge potentials
• Topological flat bands in optical checkerboard-like lattices
• Spontaneous magnetization and anomalous Hall effect in an emergent Dice lattice
• Theory of non-Hermitian fermionic superfluidity on a honeycomb lattice: Interplay between exceptional manifolds and van Hove Singularity
• Perfect optical coherence lattices
• Multiband-Driven Superfluid-Insulator Transition of Fermionic Atoms in Optical Lattices: A Dynamical Mean-Field-Theory Study
• Stripe Formation in Fermionic Atoms on 2-D Optical Lattice inside a Box Trap: DMRG Studies for Repulsive Hubbard Model with Open Boundary Condition
• Effects of disorder on atomic density waves and spin-singlet dimers in one-dimensional optical lattices
• Spatially-modulated Superfluid States in Fermionic Optical Ladder Systems with Repulsive Interactions
• Optical Feshbach resonances through a molecular dark state: Efficient manipulation of $p$-wave resonances in fermionic ${}^{171}$Yb atoms
• Feasibility of a Fulde-Ferrell-Larkin-Ovchinnikov superfluid Fermi atomic gas
• Correlated Phases of Population Imbalanced Fermi-Fermi Mixtures on an Optical Lattice
• FFLO order in ultra-cold atoms in three-dimensional optical lattices
• Spin dynamics dominated by superexchange via virtual molecules
• Heteronuclear quantum gas mixtures
• Realizing the strongly correlated $d$-Mott state in a fermionic cold atom optical lattice
• Production of a highly degenerate Fermi gas of metastable helium-3 atoms
• Magnetic phases of one-dimensional lattices with 2 to 4 fermions per site
• Tunneling properties of a bound pair of Fermi atoms in an optical lattice
• Superfluidity of fermions with repulsive on-site interaction in an anisotropic optical lattice near a Feshbach resonance
• Phase diagram of imbalanced fermions in optical lattices
• Phase diagram of non-Hermitian BCS superfluids in a dissipative asymmetric Hubbard model
• Interband physics in an ultra-cold Fermi gas in an optical lattice
• Adiabatic cooling of a tunable Bose-Fermi mixture in an optical lattice
• Charge-impurity-induced Majorana fermions in topological superconductors
• Magnetism of quantum dot clusters: A Hubbard model study
• Stability of FFLO states in optical lattices with bilayer structure
• Nonequilibrium BCS-BEC crossover and unconventional FFLO superfluid in a strongly interacting driven-dissipative Fermi gas
• Phase diagram of imbalanced strongly interacting fermions on a one-dimensional optical lattice
• Incompressible states of a two-component Fermi gas in a double-well optical lattice
• Test of Particle-Assisted Tunneling for Strongly Interacting Fermions in an Optical Superlattice
• Work statistics and Entanglement across the fermionic superfluid-insulator transition
• Matter-wave interference in s-wave and p-wave Fermi condensates
• Density-Wave and Antiferromagnetic States of Fermionic Atoms in Optical Lattices
• Odd-parity topological superfluidity for fermions in a bond-centered square optical lattice
• Statistical mechanics of a Feshbach coupled Bose-Fermi gas in an optical lattice
• Spin-flip induced superfluidity in a ring of spinful hard-core bosons
• Flow and critical velocity of an imbalanced Fermi gas through an optical potential
• Polarization-induced phase separation and re-entrant transition of two component-fermions in a one-dimensional lattice
• Inducing spin-dependent tunneling to probe magnetic correlations in optical lattices
• States of fermionic atoms in an optical superlattice across a Feshbach resonance
• Pair density wave instability and Cooper pair insulators in gapped fermion systems