Proximity effects in cold atom artificial graphene
arXiv:1608.02868 · doi:10.1088/2053-1583/aa50c6
Abstract
Cold atoms in an optical lattice with brick-wall geometry have been used to mimic graphene, a two-dimensional material with characteristic Dirac excitations. Here we propose to bring such artificial graphene into the proximity of a second atomic layer with a square lattice geometry. For non-interacting fermions, we find that such bilayer system undergoes a phase transition from a graphene-like semi-metal phase, characterized by a band structure with Dirac points, to a gapped band insulator phase. In the presence of attractive interactions between fermions with pseudospin-1/2 degree of freedom, a competition between semi-metal and superfluid behavior is found at the mean-field level. Using the quantum Monte Carlo method, we also investigate the case of strong repulsive interactions. In the Mott phase, each layer exhibits a different amount of long-range magnetic order. Upon coupling both layers, a valence-bond crystal is formed at a critical coupling strength. Finally, we discuss how these bilayer systems could be realized in existing cold atom experiments.
8 figures
References in corpus (29)
- The electronic properties of graphene
- Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
- Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene
- Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
- Bose-Einstein Condensation in Magnetic Insulators
- Observation of antiferromagnetic correlations in the Hubbard model with ultracold atoms
- Spin and Charge Resolved Quantum Gas Microscopy of Antiferromagnetic Order in Hubbard Chains
- A lattice of double wells for manipulating pairs of cold atoms
- Merging of Dirac points in a two-dimensional crystal
- Evidence for Superfluidity of Ultracold Fermions in an Optical Lattice
- Observation of Spatial Charge and Spin Correlations in the 2D Fermi-Hubbard Model
- Site-resolved measurement of the spin-correlation function in the Hubbard model
- Multi-Component Quantum Gases in Spin-Dependent Hexagonal Lattices
- Simulation and detection of Dirac fermions with cold atoms in an optical lattice
- An Aharonov-Bohm interferometer for determining Bloch band topology
- A new magnetic field dependence of Landau levels on a graphene like structure
- Extremal transmission at the Dirac point of a photonic band structure
- Two-dimensional Mott-Hubbard electrons in an artificial honeycomb lattice
- Dirac-point engineering and topological phase transitions in honeycomb optical lattices
- Making Massless Dirac Fermions from Patterned Two-Dimensional Electron Gases
- BCS-BEC crossover on the two-dimensional honeycomb lattice
- Ultracold Fermions in a Graphene-Type Optical Lattice
- Spin-Orbit Coupling and Spin Textures in Optical Superlattices
- Dirac Point and Edge States in a Microwave Realization of Tight-Binding Graphene-like Structures
- Quantum Simulation of the Hubbard Model: The Attractive Route
- Plasmons and Coulomb drag in Dirac/Schroedinger hybrid electron systems
- Proximity effect and Majorana bound states in clean semiconductor nanowires coupled to disordered superconductors
- Double transfer through Dirac points in a tunable honeycomb optical lattice
- Beyond mean-field study of a binary bosonic mixture in a state-dependent honeycomb lattice
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- Atomic Bose-Einstein condensate in a twisted-bilayer optical lattice
- Cold atoms in twisted bilayer optical potentials
- Simulating twistronics without a twist
- Spin-twisted Optical Lattices: Tunable Flat Bands and Larkin-Ovchinnikov Superfluids
- Symmetry protected topological phases characterized by isolated exceptional points
- Synthetic dimensions for topological and quantum phases: Perspective
- Quantum anomalous Hall phase in synthetic bilayers via twistless twistronics
- Reentrant Fulde-Ferrell-Larkin-Ovchinnikov superfluidity in the honeycomb lattice
- Flat-band-induced superconductivity in synthetic bilayer optical lattices
- Layer-by-layer assembly of multilayer optical lattices: Application to displaced dice lattice
- Topological Transitions in a Model for Proximity Induced Superconductivity