Relaxation dynamics of ultracold bosons in a double-well potential: Thermalization and prethermalization in a nearly integrable model

Abstract

We numerically investigate the relaxation dynamics in an isolated quantum system of interacting bosons trapped in a double-well potential after an integrability breaking quench. Using the statistics of the spectrum, we identify the postquench Hamiltonian as nonchaotic and close to integrability over a wide range of interaction parameters. We demonstrate that the system exhibits thermalization in the context of the eigenstate thermalization hypothesis (ETH). We also explore the possibility of an initial state to delocalize with respect to the eigenstates of the postquench Hamiltonian even for energies away from the middle of the spectrum. We observe distinct regimes of equilibration process depending on the initial energy. For low energies, the system rapidly relaxes in a single step to a thermal state. As the energy increases towards the middle of the spectrum, the relaxation dynamics exhibits prethermalization and the lifetime of the metastable states grows. Time evolution of the occupation numbers and the von Neumann entropy in the mode-partitioned system underpins the analyses of the relaxation dynamics.

14 pages, 13 figures

References in corpus (19)

• Many-Body Physics with Ultracold Gases
• Thermalization and its mechanism for generic isolated quantum systems
• Localization of interacting fermions at high temperature
• The distribution of the ratio of consecutive level spacings in random matrix ensembles
• Experimental Observation of a Generalized Gibbs Ensemble
• Interaction Quench in the Hubbard model
• Testing whether all eigenstates obey the Eigenstate Thermalization Hypothesis
• Eigenstate thermalization hypothesis (ETH) and integrability in quantum spin chains
• Quantum chaos and thermalization in gapped systems
• Relaxation and thermalization in the one-dimensional Bose-Hubbard model: A case study for the interaction quantum quench from the atomic limit
• Quantum Quenches in the Thermodynamic Limit
• Statistical properties of the spectrum the extended Bose-Hubbard model
• General Features of the Relaxation Dynamics of Interacting Quantum Systems
• Quantum Quench and Prethermalization Dynamics in A Two-Dimensional Fermi Gas with Long-range Interactions
• Relevance of the eigenstate thermalization hypothesis for thermal relaxation
• Nonexponential fidelity decay in isolated interacting quantum systems
• Thermalization of entanglement
• Tunneling, self-trapping and manipulation of higher modes of a BEC in a double well
• Thermalization in closed quantum systems: semiclassical approach

Cited by in corpus (5)

• Nonthermal states arising from confinement in one and two dimensions
• Signatures of rare states and thermalization in a theory with confinement
• Infinite Barriers and Symmetries for a Few Trapped Particles in One Dimension
• Interaction blockade for bosons in an asymmetric double well
• Hierarchical relaxation dynamics in a tilted two-band Bose-Hubbard model