title: The multi-layer multi-configuration time-dependent Hartree method for bosons: theory, implementation, and applications.
abstract: We develop the multi-layer multi-configuration time-dependent Hartree method for bosons (ML-MCTDHB), a variational numerically exact ab initio method for studying the quantum dynamics and stationary properties of general bosonic systems. ML-MCTDHB takes advantage of the permutation symmetry of identical bosons, which allows for investigations of the quantum dynamics from few to many-body systems. Moreover, the multi-layer feature enables ML-MCTDHB to describe mixed bosonic systems consisting of arbitrary many species. Multi-dimensional as well as mixed-dimensional systems can be accurately and efficiently simulated via the multi-layer expansion scheme. We provide a detailed account of the underlying theory and the corresponding implementation. We also demonstrate the superior performance by applying the method to the tunneling dynamics of bosonic ensembles in a one-dimensional double well potential, where a single-species bosonic ensemble of various correlation strengths and a weakly interacting two-species bosonic ensemble are considered.
authors.affiliation: Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany.
authors.forename: Lushuai
authors.initials: L
authors.lastname: Cao
authors.forename: Sven
authors.initials: S
authors.lastname: Krönke
authors.forename: Oriol
authors.initials: O
authors.lastname: Vendrell
authors.forename: Peter
authors.initials: P
authors.lastname: Schmelcher