Many-body Landau-Zener tunneling in the Bose-Hubbard model

TL;DR

This paper investigates many-body Landau-Zener tunneling in ultracold atoms within the Bose-Hubbard model, analyzing spectral properties and interband tunneling to characterize the transition from regular to chaotic quantum regimes.

Contribution

It introduces a many-body approach to study Landau-Zener tunneling, including interband effects, and links spectral statistics to the regular-chaotic transition in ultracold atomic systems.

Findings

Spectral statistics reveal the transition from regular to chaotic regimes.

Distribution of tunneling rates serves as an experimental signature of chaos.

Interband tunneling rates are quantitatively characterized in a many-body context.

Abstract

We study a model for ultracold, spinless atoms in quasi-one dimensional optical lattices and subjected to a tunable tilting force. Statistical tests are employed to quantitatively characterize the spectrum of the Floquet-Bloch operator of the system along the transition from the regular to the quantum chaotic regime. Moreover, we perturbatively include the coupling of the one-band model to the second energy band. This allows us to study the Landau-Zener interband tunneling within a truly many-body description of ultracold atoms. The distributions of the computed tunneling rates provide an independent and experimentally accessible signature of the regular-chaotic transition.