Quantum Phases and Collective Excitations in Bose-Hubbard Models with Staggered Magnetic Flux

Abstract

We study the quantum phases of a Bose-Hubbard model with staggered magnetic flux in two dimensions, as has been realized recently [Aidelsburger {\it et al.}, PRL, {\bf 107}, 255301 (2011)]. Within mean field theory, we show how the structure of the condensates evolves from weak to strong coupling limit, exhibiting a tricritical point at the Mott-superfluid transition. Non-trivial topological structures (Dirac points) in the quasi-particle (hole) excitations in the Mott state are found within random phase approximation and we discuss how interaction modifies their structures. Excitation gap in the Mott state closes at different $\mathbf{k}$ points when approaching the superfluid states, which is consistent with the findings of mean field theory.

5 pages, 3 figures

References in corpus (6)

• Spin-Injection Spectroscopy of a Spin-Orbit Coupled Fermi Gas
• Tunable gauge potential for neutral and spinless particles in driven lattices
• A Bose-Einstein Condensate in a Uniform Light-induced Vector Potential
• Staggered-Vortex Superfluid of Ultracold Bosons in an Optical Lattice
• Condensed Groundstates of Frustrated Bose-Hubbard Models
• Interacting Hofstadter spectrum of atoms in an artificial gauge field

Cited by in corpus (4)

• Chiral Bosonic Phases on the Haldane Honeycomb Lattice
• Strong Interaction Effects in Superfluid Ising Quantum Phase Transition
• Two-leg ladder Bose Hubbard models with staggered fluxes
• Finite size effects and Hofstadter butterfly in a bosonic Mott insulator with relativistic dispersion background