Resonant quantum dynamics of few ultracold bosons in periodically driven finite lattices

TL;DR

This paper investigates the resonant quantum dynamics of a few ultracold bosons in periodically driven finite optical lattices, revealing in-phase oscillations, resonance phenomena, and the effects of interactions and lattice parameters.

Contribution

It provides a detailed analysis of resonance behavior and excitation spectra in driven bosonic lattices using ab-initio methods, highlighting the role of interactions and driving frequency.

Findings

Resonance induces in-phase oscillations of bosons in different wells.

Rich intraband excitation spectrum appears near resonance.

Interactions significantly alter tunneling and excitation probabilities.

Abstract

The out-of-equilibrium dynamics of finite ultracold bosonic ensembles in periodically driven one-dimensional optical lattices is investigated. Our study reveals that the driving enforces the bosons in different wells to oscillate in-phase and to exhibit a dipole-like mode. A wide range from weak-to-strong driving frequencies is covered and a resonance-like behaviour of the intra-well dynamics is discussed. In the proximity of the resonance a rich intraband excitation spectrum is observed. The single particle excitation mechanisms are studied in the framework of Floquet theory elucidating the role of the driving frequency. The impact of the interatomic repulsive interactions is examined in detail yielding a strong influence on the tunneling period and the excitation probabilities. Finally, the dependence of the resonance upon a variation of the tunable parameters of the optical lattice is examined. Our analysis is based on the ab-initio Multi-Configuration Time-Dependent Hartree Method for bosons.