Collapse and revival in inter-band oscillations of a two-band Bose-Hubbard model

TL;DR

This paper investigates how many-body interactions influence inter-band oscillations in a two-band Bose-Hubbard model under Stark force, revealing collapse and revival phenomena and developing effective models to predict these dynamics.

Contribution

It introduces effective models that describe collapse and revival of inter-band oscillations caused by weak two-body interactions in a two-band Bose-Hubbard system.

Findings

Weak and strong inter-band oscillations observed.

Oscillations collapse and revive due to interactions.

Predictions for collapse and revival time-scales provided.

Abstract

We study the effect of a many-body interaction on inter-band oscillations in a two-band Bose-Hubbard model with external Stark force. Weak and strong inter-band oscillations are observed, where the latter arise from a resonant coupling of the bands. These oscillations collapse and revive due to a weak two-body interaction between the atoms. Effective models for oscillations in and out of resonance are introduced that provide predictions for the system's behaviour, particularly for the time-scales for the collapse and revival of the resonant inter-band oscillations.