Bose-Einstein condensate in an optical lattice with Raman-assisted two-dimensional spin-orbit coupling

Abstract

In a recent experiment by Wu {\textit et al.} (arXiv:1511.08170), a Raman-assisted two-dimensional spin-orbit coupling has been realized for a Bose-Einstein condensate in an optical lattice potential. In light of this exciting progress, we study in detail key properties of the system. As the Raman lasers inevitably couple atoms to high-lying bands, the behaviors of the system in both the single- and many-particle sectors are significantly affected. In particular, the high-band effects enhance the plane-wave phase and lead to the emergence of "roton" gaps at low Zeeman fields. Furthermore, we identify high-band-induced topological phase boundaries in both the single-particle and the quasi-particle spectra. We then derive an effective two-band model, which captures the high-band physics in the experimentally relevant regime. Our results not only offer valuable insights into the novel two-dimensional lattice spin-orbit coupling, but also provide a systematic formalism to model high-band effects in lattice systems with Raman-assisted spin-orbit couplings.

10 pages, 5 figures

References in corpus (8)

• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Degenerate Quantum Gases with Spin-Orbit Coupling
• Anisotropic dynamics of a spin-orbit coupled Bose-Einstein condensate
• Softening of Roton and Phonon Modes in a Bose-Einstein Condensate with Spin-Orbit Coupling
• Roton-Maxon Excitation Spectrum of Bose Condensates in a Shaken Optical Lattice
• Measurement of collective excitations in a spin-orbit-coupled Bose-Einstein condensate
• Topological Bogoliubov excitations in inversion-symmetric systems of interacting bosons
• Topological Fulde-Ferrell Superfluids of a Spin-Orbit Coupled Fermi Gas

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• Spin-orbit coupling and topological phases for ultracold atoms
• Dirac surface states in magnonic analogs of topological crystalline insulators
• Bloch oscillations of spin-orbit-coupled cold atoms in an optical lattice and spin current generation
• Dynamically characterizing topological phases by high-order topological charges
• Stückelberg interferometry using spin-orbit-coupled cold atoms in an optical lattice
• Interaction induced topological Bogoliubov excitations in a spin-orbit coupled Bose-Einstein condensate
• Polaron in a $p+ip$ Fermi topological superfluid
• Bosonic Topological Excitations from the Instability of a Quadratic Band Crossing
• Interaction-induced exotic vortex states in an optical lattice clock with spin-orbit coupling
• Topological Bogoliubov quasiparticles from Bose-Einstein condensate in a flat band system
• Intrinsic anomalous Hall effect across the magnetic phase transition of a spin-orbit-coupled Bose-Einstein condensate
• Bloch bound state of spin-orbit-coupled fermions in an optical lattice
• Repulsive Fermi gases in a two-dimensional lattice with non-Abelian gauge fields
• Nonadiabatic decay of metastable states on coupled linear potentials
• Topological Higgs Amplitude Modes in Strongly Interacting Superfluids
• Topological phases protected by projective space-time inversion symmetry in alkaline-earth-metal-like atoms
• Band-edge superfluid of Bose-Einstein condensates in the spin-orbit-coupled Zeeman lattice
• Supersolid Devil's Staircases of Spin-Orbit-Coupled Bosons in Optical Lattices