Dynamical properties of ultracold bosons in an optical lattice

Abstract

We study the excitation spectrum of strongly correlated lattice bosons for the Mott-insulating phase and for the superfluid phase close to localization. Within a Schwinger-boson mean-field approach we find two gapped modes in the Mott insulator and the combination of a sound mode (Goldstone) and a gapped (Higgs) mode in the superfluid. To make our findings comparable with experimental results, we calculate the dynamic structure factor as well as the linear response to the optical lattice modulation introduced by Stoeferle et al. [Phys. Rev. Lett. 92, 130403 (2004)]. We find that the puzzling finite frequency absorption observed in the superfluid phase could be explained via the excitation of the gapped (Higgs) mode. We check the consistency of our results with an adapted f-sum-rule and propose an extension of the experimental technique by Stoeferle et al. to further verify our findings.

13 pages, 5 figures

References in corpus (5)

• Mott insulators in strong electric fields
• Quantum Monte Carlo simulations of confined bosonic atoms in optical lattices
• Mott insulator to superfluid transition in the Bose-Hubbard model: a strong-coupling approach
• Spectroscopy of ultracold atoms by periodic lattice modulations
• Signatures of the superfluid to Mott-insulator transition in the excitation spectrum of ultracold atoms

Cited by in corpus (31)

• Many-Body Physics with Ultracold Gases
• Quantum fluids of light
• Amplitude / Higgs Modes in Condensed Matter Physics
• The `Higgs' Amplitude Mode at the Two-Dimensional Superfluid-Mott Insulator Transition
• Spreading of correlations and entanglement after a quench in the one-dimensional Bose-Hubbard model
• Bose condensation in flat bands
• Rise and fall of hidden string order of lattice bosons
• Exploring correlated 1D Bose gases from the superfluid to the Mott-insulator state by inelastic light scattering
• Detecting the Amplitude Mode of Strongly Interacting Lattice Bosons by Bragg Scattering
• The Higgs mode in a two-dimensional superfluid
• Correlated bosons on a lattice: Dynamical mean-field theory for Bose-Einstein condensed and normal phases
• Spectral weight redistribution in strongly correlated bosons in optical lattices
• Excitation spectra of strongly correlated lattice bosons and polaritons
• The Amplitude Mode in the Quantum Phase Model
• Self-consistent slave rotor mean field theory for strongly correlated systems
• Characterization of Mott-insulating and superfluid phases in the one-dimensional Bose--Hubbard model
• Superfluid to Mott-insulator transition in Bose-Hubbard models
• Bose-Hubbard model with occupation dependent parameters
• Dynamically Generated Double Occupancy as a Probe of Cold Atom Systems
• Universal Properties of the Higgs Resonance in (2+1)-Dimensional U(1) Critical Systems
• Nonequilibrium dynamical mean-field theory for bosonic lattice models
• Variational cluster approach for strongly correlated lattice bosons in the superfluid phase
• Driven optical lattices as strong-field simulators
• Excitation Spectra of Bosons in Optical Lattices from Schwinger-Keldysh Calculation
• Real-Time Ginzburg-Landau Theory for Bosons in Optical Lattices
• Low-energy Effective Theory for One-dimensional Lattice Bosons near Integer Filling
• Superfluid to Mott-insulator transition of cold atoms in optical lattices
• Adiabatic dynamics in a spin-1 chain with uniaxial single-spin anisotropy
• Interacting bosons in an optical lattice: Bose-Einstein condensates and Mott insulator
• Upper bound of one-magnon excitation and lower bound of effective mass for ferromagnetic spinor Bose and Fermi gases
• Mesoscopic Aspects of Strongly Interacting Cold Atoms