Floquet-Band Engineering of Shaken Bosonic Condensates

TL;DR

This paper introduces new numerical methods for simulating shaken bosonic condensates, enabling more accurate modeling of their Floquet band structures and interactions, with results aligning well with experimental data.

Contribution

The authors develop direct lattice shaking simulation techniques that avoid simplifying assumptions, allowing for precise modeling of driven superfluid systems with interactions.

Findings

Quantitative agreement with experimental Kibble-Zurek scaling.

Interactions induce instabilities affecting Floquet band behavior.

New methods enable detailed study of driven superfluid dynamics.

Abstract

Optical control and manipulation of cold atoms has become an important topic in condensed matter. Widely employed are optical lattice shaking experiments which allow the introduction of artificial gauge fields, the design of topological bandstructures, and more general probing of quantum critical phenomena. Here we develop new numerical methods to simulate these periodically driven systems by implementing lattice shaking directly. As a result we avoid the usual assumptions associated with a simplified picture based on Floquet dynamics. A demonstrable success of our approach is that it yields quantitative agreement with experiment, including Kibble-Zurek scaling. Importantly, we argue that because their dynamics corresponds to an effective non-linear Schr\"{o}dinger equation, these particular superfluid studies present a unique opportunity to address how general Floquet band engineering is affected by interactions. In particular, interactions cause instabilities at which the behavior of the system changes dramatically.