Optimized quantum state transfer in a quasiperiodic ultracold atomic gas

Abstract

Ultracold atomic systems offer a highly controllable platform for investigating quantum state transfer through the precise dynamical manipulation of system parameters. While quantized Thouless pumping has been extensively explored in these systems, adiabatic edge-to-edge transfer of localized quantum states remains largely unexplored. Here, we consider a one-dimensional ultracold atomic gas confined in a bichromatic optical lattice realizing a quasiperiodic Aubry--Andr\'e--Harper system. We use its edge-localized winding states to implement quantum state transfer between opposite boundaries. Starting from the instantaneous spectral properties of the corresponding tight-binding model, we construct locally adiabatic protocols and extend the approach to higher protocol orders. We then simulate their dynamics under the full continuum bichromatic-lattice Hamiltonian. Our results reveal a tradeoff between edge localization and the minimum spectral gap: strongly localized states require longer transfer times, but can benefit substantially from higher protocol orders. We are also able to capture the main fidelity trends and coherent oscillations over a broad parameter regime using an effective two-level Landau--Zener description. Our results provide practical guidelines for selecting experimentally accessible parameters and tailoring quantum transfer protocols in quasiperiodic ultracold atomic systems.