Chiral spin superfluidity and spontaneous spin Hall effect of interacting bosons

Abstract

Recent experiments on ultracold atoms in optical lattices have synthesized a variety of tunable bands with degenerate double-well structures in momentum space. Such degeneracies in the single particle spectrum strongly enhance quantum fluctuations, and may lead to exotic many-body ground states. Here we consider weakly interacting spinor Bose gases in such bands, and discover a universal quantum "order by disorder" phenomenon which selects a novel chiral spin superfluid with remarkable properties such as spontaneous anomalous spin Hall effect and momentum space antiferromagnetism. For bosons in the excited Dirac band of a hexagonal lattice, such a state supports staggered spin loop currents in real space. We show that Bloch oscillations provide a powerful dynamical route to quantum state preparation of such a chiral spin superfluid. Our predictions can be readily tested in spin resolved time-of-flight experiments.

7+4 pages, 6 figures

References in corpus (12)

• The Valley Hall Effect in MoS2 Transistors
• Spin-orbit coupling in quantum gases
• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Bose-Einstein Condensation in Magnetic Insulators
• Topological Mott Insulators
• Observation of the Meissner effect with ultracold atoms in bosonic ladders
• Orbital superfluidity in the $P$-band of a bipartite optical square lattice
• Observation of Quantized Conductance in Neutral Matter
• Interaction-controlled transport of an ultracold Fermi gas
• Superfluidity of Bosons in Kagome Lattices with Frustration
• Exact Results on Itinerant Ferromagnetism in Multi-orbital Systems on Square and Cubic Lattices
• Spontaneous loop-spin current with topological characters in the Hubbard model

Cited by in corpus (9)

• Chiral Bosonic Phases on the Haldane Honeycomb Lattice
• Chiral Induced Spin Selectivity as a Spontaneous Intertwined Order
• Static and Dynamic Properties of Interacting Spin-1 Bosons in an Optical Lattice
• Chiral Mott insulators in frustrated Bose-Hubbard models on ladders and two-dimensional lattices: a combined perturbative and density matrix renormalization group study
• Twisted superfluid phase in the extended one-dimensional Bose-Hubbard model
• Twisted superfluid and supersolid phases of triplons in bilayer honeycomb magnets
• Absence of Landau damping in driven three-component Bose-Einstein condensate in optical lattices
• Damping-free collective oscillations of a driven two-component Bose gas in optical lattices
• Chiral Spin Condensation in a One-Dimensional Optical Lattice