Valley-dependent gauge fields for ultracold atoms in square optical superlattices

Abstract

We propose an experimental scheme to realize the valley-dependent gauge fields for ultracold fermionic atoms trapped in a state-dependent square optical lattice. Our scheme relies on two sets of Raman laser beams to engineer the hopping between adjacent sites populated by two-component fermionic atoms. One set of Raman beams are used to realize a staggered π-flux lattice, where low energy atoms near two inequivalent Dirac points should be described by the Dirac equation for spin-1/2 particles. Another set of laser beams with proper Rabi frequencies are added to further modulate the atomic hopping parameters. The hopping modulation will give rise to effective gauge potentials with opposite signs near the two valleys, mimicking the interesting strain-induced pseudo-gauge fields in graphene. The proposed valley-dependent gauge fields are tunable and provide a new route to realize quantum valley Hall effects and atomic valleytronics.

5+ pages, 2 figures; language polished, references and discussions added; accepted by PRA

References in corpus (21)

• The electronic properties of graphene
• Valley filter and valley valve in graphene
• Realization of the Hofstadter Hamiltonian with ultracold atoms in optical lattices
• Realizing the Harper Hamiltonian with Laser-Assisted Tunneling in Optical Lattices
• All-graphene integrated circuits via strain engineering
• Intervalley scattering, long-range disorder, and effective time reversal symmetry breaking in graphene
• Edge states in Graphene: from gapped flat band to gapless chiral modes
• Engineering Time-Reversal Invariant Topological Insulators With Ultra-Cold Atoms
• Realistic Time-Reversal Invariant Topological Insulators With Neutral Atoms
• Simulation and detection of Dirac fermions with cold atoms in an optical lattice
• Spin Hall effects for cold atoms in a light induced gauge potential
• The spin Hall effect in a quantum gas
• Non-Abelian optical lattices: Anomalous quantum Hall effect and Dirac Fermions
• Optical Flux Lattices for Ultracold Atomic Gases
• Sublattice addressing and spin-dependent motion of atoms in a double-well lattice
• Realizing and Detecting the Haldane's Quantum Hall effect with Ultracold Atoms
• Staggered-Vortex Superfluid of Ultracold Bosons in an Optical Lattice
• Relativistic quantum effects of Dirac particles simulated by ultracold atoms
• Massless Dirac Fermions in a Square Optical Lattice
• Non-abelian gauge fields and quadratic band touchings in molecular graphene
• Non-Abelian SU(2) gauge fields through density-wave order and strain in graphene

Cited by in corpus (5)

• Topological Phases in Two-Dimensional Materials: A Brief Review
• Simulation and measurement of the fractional particle number in one-dimensional optical lattices
• Competing charge-density-wave, magnetic and topological ground states at and near Dirac points in graphene in axial magnetic fields
• Emulating topological currents arising from a dipolar parity anomaly in two-dimensional optical lattices
• Topology and criticality in non-Hermitian multimodal optical resonators through engineered losses