Ultracold Bose gases in time-dependent 1D superlattices: response and quasimomentum structure

TL;DR

This paper investigates the dynamic response and quasimomentum structure of ultracold Bose gases in time-dependent 1D superlattices using simulations of the Bose-Hubbard model, revealing correlations between excitation frequency and momentum distribution.

Contribution

It provides new insights into the quasimomentum behavior and energy transfer in Bose gases under modulated superlattice potentials, extending understanding of their dynamical properties.

Findings

Identified correlations between excitation frequency and quasimomentum distribution.

Analyzed the effects of superlattice potential on excitation and momentum structure.

Studied the system's response in the Mott-insulator phase under small-amplitude modulations.

Abstract

The response of ultracold atomic Bose gases in time-dependent optical lattices is discussed based on direct simulations of the time-evolution of the many-body state in the framework of the Bose-Hubbard model. We focus on small-amplitude modulations of the lattice potential as implemented in several recent experiment and study different observables in the region of the first resonance in the Mott-insulator phase. In addition to the energy transfer we investigate the quasimomentum structure of the system which is accessible via the matter-wave interference pattern after a prompt release. We identify characteristic correlations between the excitation frequency and the quasimomentum distribution and study their structure in the presence of a superlattice potential.