Memory effects in a quasi-periodic Fermi lattice

Abstract: We investigate a system of fermions trapped in a quasi-periodic potential from an open quantum system theory perspective, designing a protocol in which an impurity atom (a two level system) is coupled to a trapped fermionic cloud described by the non-interacting Aubry-Andr\'e model. The Fermi system is prepared in a charge density wave state before it starts its relaxation. In this work we focus our attention on the time evolution of the impurity in such an out of equilibrium environment, and study whether the induced dynamics can be classified as Markovian or non-Markovian. We find how the localised phase of the Aubry-Andr\'{e} model displays evidence of strong and stable memory effects and can be considered as a controllable and robust non-Markovian environment.