Quantum bright solitons in a quasi-one-dimensional optical lattice

Abstract

We study a quasi-one-dimensional attractive Bose gas confined in an optical lattice with a superimposed harmonic potential by analyzing the effective one-dimensional Bose-Hubbard Hamiltonian of the system. In order to have a reliable description of the ground-state, that we call quantum bright soliton, we use the Density-Matrix-Renormalization-Group (DMRG) technique. By comparing DMRG results with mean-field (MF) ones we find that beyond-mean-field effects become relevant by increasing the attraction between bosons or by decreasing the frequency of the harmonic confinement. In particular we discover that, contrary to the MF predictions based on the discrete nonlinear Schrödinger equation, quantum bright solitons are not self-trapped. We also use the time-evolving-block-decimation (TEBD) method to investigate dynamical properties of bright solitons when the frequency of the harmonic potential is suddenly increased. This quantum quench induces a breathing mode whose period crucially depends on the final strength of the super-imposed harmonic confinement.

References in corpus (3)

• Many-Body Physics with Ultracold Gases
• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Formation of bright matter-wave solitons during the collapse of Bose-Einstein condensates

Cited by in corpus (12)

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• Repulsive to attractive interaction quenches of 1D Bose gas in a harmonic trap
• From short-time diffusive to long-time ballistic dynamics: the unusual center-of-mass motion of quantum bright solitons
• Quantum bright solitons in the Bose-Hubbard model with site-dependent repulsive interactions
• Harmonically trapped attractive and repulsive spin-orbit and Rabi coupled Bose-Einstein condensates
• Matter-waves in Bose-Einstein condensates with spin-orbit and Rabi couplings
• Dimensional reduction and localization of a Bose-Einstein condensate in a quasi-1D bichromatic optical lattice
• Discrete bright solitons in Bose-Einstein condensates and dimensional reduction in quantum field theory
• Quantum theory of fractional topological pumping of lattice solitons
• Localized-Interaction-Induced Quantum Reflection and Filtering of Bosonic Matter in a One-Dimensional Lattice Guide
• Extracting atoms one by one from a small matter-wave soliton