Many-body Landau-Zener dynamics in coupled one-dimensional Bose liquids

The Landau-Zener model of a quantum mechanical two-level system driven with a linearly time-dependent detuning has served over decades as a textbook model of quantum dynamics. In their seminal work, Landau and Zener derived a non-perturbative prediction for the transition probability between two states, which often serves as a reference point for the analysis of more complex systems. A particularly intriguing question is whether that framework can be extended to describe many-body quantum dynamics. Here we report an experimental and theoretical study of a system of ultracold atoms, offering a direct many-body generalization of the Landau-Zener problem. In a system of pairwise tunnel-coupled one-dimensional (1D) Bose liquids we show how tuning the correlations of the 1D gases and the tunnel coupling between the tubes strongly modify the original Landau-Zener picture. The results are explained using a mean-field description of the inter-tube condensate wavefunction, coupled to the low-energy phonons of the 1D Bose liquid.