Memory effects in a quasiperiodic Fermi lattice

Abstract

We investigate a system of fermions trapped in a quasiperiodic 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 noninteracting 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 localized 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.