Collective and single-particle excitations in 2D dipolar Bose gases

Abstract

The Berezinskii-Kosterlitz-Thouless transition in 2D dipolar systems has been studied recently by path integral Monte Carlo (PIMC) simulations [A. Filinov et al., PRL 105, 070401 (2010)]. Here, we complement this analysis and study temperature-coupling strength dependence of the density (particle-hole) and single-particle (SP) excitation spectra both in superfluid and normal phases. The dynamic structure factor, S(q,omega), of the longitudinal excitations is rigorously reconstructed with full information on damping. The SP spectral function, A(q,omega), is worked out from the one-particle Matsubara Green's function. A stochastic optimization method is applied for reconstruction from imaginary times. In the superfluid regime sharp energy resonances are observed both in the density and SP excitations. The involved hybridization of both spectra is discussed. In contrast, in the normal phase, when there is no coupling, the density modes, beyond acoustic phonons, are significantly damped. Our results generalize previous zero temperature analyses based on variational many-body wavefunctions [F. Mazzanti et al., PRL 102, 110405 (2009), D. Hufnagl et al., PRL 107, 065303 (2011)], where the underlying physics of the excitation spectrum and the role of the condensate has not been addressed.

arXiv comment27 pages, 15 figures, 7 tables

References in corpus (41)

• Quantum information with Rydberg atoms
• A High Phase-Space-Density Gas of Polar Molecules
• Continuous-time Monte Carlo methods for quantum impurity models
• The physics of dipolar bosonic quantum gases
• Bose-Einstein condensation of chromium
• Quantum-State Controlled Chemical Reactions of Ultracold KRb Molecules
• A Strongly Dipolar Bose-Einstein Condensate of Dysprosium
• Bose-Einstein Condensation of Erbium
• Quantum-fluid dynamics of microcavity polaritons
• Roton-maxon spectrum and stability of trapped dipolar condensates
• Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential
• Observation of dipole-dipole interaction in a degenerate quantum gas
• Worm Algorithm and Diagrammatic Monte Carlo: A New Approach to Continuous-Space Path Integral Monte Carlo Simulations
• Quantum Gas of Deeply Bound Ground State Molecules
• Ultracold Molecules in the Ro-Vibrational Triplet Ground State
• Trapped atomic condensates with anisotropic interactions
• Strongly correlated gases of Rydberg-dressed atoms: quantum and classical dynamics
• Radial and angular rotons in trapped dipolar gases
• Quantum phase transition in a two-dimensional system of dipoles
• Stability of quasi-two-dimensional Bose-Einstein condensates with dominant dipole-dipole interactions
• Rotons in gaseous Bose-Einstein condensates irradiated by a laser
• Manifestations of the Roton Mode in Dipolar Bose-Einstein Condensates
• Exciton correlations in coupled quantum wells and their luminescence blue shift
• Crystallization dynamics of a single layer complex plasma
• Ab-initio low-energy dynamics of superfluid and solid 4He
• Two-photon ionization of Helium studied with the multiconfigurational time-dependent Hartree-Fock method
• Berezinskii-Kosterlitz-Thouless transition in two-dimensional dipole systems
• Trapping of Cold Excitons with Laser Light
• Ab initio calculation of the KRb dipole moments
• Many-body Rabi oscillations of Rydberg excitation in small mesoscopic samples
• Trapping Long-Lifetime Excitons in a Two-Dimensional Harmonic Potential
• Dynamics of two-dimensional dipole systems
• Crystallization of an exciton superfluid
• Remote Dipolar Interactions for Objective Density Calibration and Flow Control of Excitonic Fluids
• Correlational Origin of the Roton Minimum
• Structure, Bose-Einstein condensation and superfluidity of two-dimensional confined dipolar assemblies
• Bose-Einstein condensation of trapped atoms with dipole interactions
• Mesoscopic supersolid of dipoles in a trap
• Quasiequilibrium supersolid phase of a two-dimensional dipolar crystal
• Weakly interacting two-dimensional system of dipoles: limitations of mean-field theory
• Theoretical study of the dynamic structure factor of superfluid 4He

Cited by in corpus (30)

• The Uniform Electron Gas at Warm Dense Matter Conditions
• Ab initio simulation of warm dense matter
• The Fermion Sign Problem in Path Integral Monte Carlo Simulations: Quantum Dots, Ultracold Atoms, and Warm Dense Matter
• Ab Initio Path Integral Monte Carlo Approach to the Static and Dynamic Density Response of the Uniform Electron Gas
• First principles simulations of dense hydrogen
• \emph{Ab initio} Quantum Monte Carlo simulation of the warm dense electron gas
• Excitons and biexcitons in symmetric electron-hole bilayers
• Dynamic properties of the warm dense electron gas: an ab initio path integral Monte Carlo approach
• Path Integral Monte Carlo Simulation of Degenerate Electrons: Permutation-Cycle Properties
• Nonlinear density response from imaginary-time correlation functions: Ab initio path integral Monte Carlo simulations of the warm dense electron gas
• Attenuating the fermion sign problem in path integral Monte Carlo simulations using the Bogoliubov inequality and thermodynamic integration
• Finite-size effects in the reconstruction of dynamic properties from ab initio path integral Monte-Carlo simulations
• Correlation effects and collective excitations in bosonic bilayers: role of quantum statistics, superfluidity and dimerization transition
• Ab initio path integral Monte Carlo simulation of the Uniform Electron Gas in the High Energy Density Regime
• Fermion Sign Problem in Path Integral Monte Carlo Simulations: Grand-canonical ensemble
• Extraction of the frequency moments of spectral densities from imaginary-time correlation function data
• Analysis of dynamical effects in the uniform electron liquids with the self-consistent method of moments complemented by the Shannon information entropy and the path-integral Monte-Carlo simulations
• Stability and excitations of a bilayer of strongly correlated dipolar Bosons
• Ab initio Path Integral Monte Carlo Simulations of Quantum Dipole Systems in Traps: Superfluidity, Quantum Statistics, and Structural Properties
• Applying the Liouville-Lanczos Method of Time-Dependent Density-Functional Theory to Warm Dense Matter
• Estimates of the dynamic structure factor for the finite temperature electron liquid via analytic continuation of path integral Monte Carlo data
• Energy response and spatial alignment of the perturbed electron gas
• The Multi-component Correlated Basis Function Method and its Application to Multilayered Dipolar Bose Gases
• Nonequilibrium Green's function approach to the pair distribution function of quantum many-body systems out of equilibrium
• Electronic rotons and Wigner crystallites in a two-dimensional dipole liquid
• Dynamic properties and the roton mode attenuation in the liquid 3He: an ab initio study within the self-consistent method of moments
• Characterization of the energy level-structure of a trapped dipolar Bose gas via mean-field parametric resonances
• PyLIT: Reformulation and implementation of the analytic continuation problem using kernel representation methods
• The noiseless limit and improved-prior limit of the maximum entropy method and their implications for the analytic continuation problem
• Path Integral Monte Carlo Simulations of liquid ${}^3$He without Fixed Nodes: Structural Properties and Collective Excitations