Phase diagram of Landau-Zener phenomena in coupled one-dimensional Bose quantum fluids

TL;DR

This paper explores the many-body Landau-Zener dynamics in coupled one-dimensional Bose fluids, revealing a complex phase diagram and contrasting behaviors between ground-state and inverse sweeps, with implications for quantum control.

Contribution

It provides a detailed phase diagram of transfer efficiency in many-body Landau-Zener processes, highlighting differences from single-particle schemes and identifying a critical interaction strength.

Findings

Breakdown of adiabaticity at low sweep rates for ground-state sweeps

Transfer efficiency aligns with single-particle predictions during inverse sweeps

Existence of a critical interaction strength where particle transfer ceases

Abstract

We study stationary and dynamical properties of the many-body Landau-Zener dynamics of a Bose quantum fluid confined in two coupled one-dimensional chains, using a many-body generalization recently reported [Y.-A. Chen et al.], within the decoupling approximation and the one-level band scheme. The energy spectrum evidences the structure of the avoided level crossings as a function of the on-site inter particle interaction strength. On the dynamical side, a phase diagram of the transfer efficiency across ground-state and inverse sweeps is presented. A totally different scenario with respect to the original single-particle Landau-Zener scheme is found for ground-state sweeps, in which a breakdown of the adiabatic region emerges as the sweep rate decreases. On the contrary, the transfer efficiency across inverse sweeps reveals consistent results with the single-particle Landau-Zener predictions. In the strong coupling regime, we find that there is a critical value of the on-site interaction for which the transfer of particles starts to vanish independently of the sweep rate. Our results are in qualitative agreement with those of the experimental counterpart.