title: Quantum Zeno-type effect and non-Markovianity in a three-level system.
abstract: We study the coexistence of the quantum Zeno-type effect and non-Markovianity for a system decaying in a structured bosonic environment and subject to a control field. The interaction with the environment induces decay from the excited to the ground level, which, in turn, is coherently coupled to another meta-stable state. The control of the strength of the coherent coupling between the stable levels allows the engineering of both the dissipation and of the memory effects, without modifying neither the system-reservoir interaction, nor environmental properties. We use this framework in two different parameter regimes corresponding to fast (bad cavity limit) and slow dissipation (good cavity limit) in the original and un-controlled qubit system. Our results show a non-monotonic behavior of memory effects when increasing the effectiveness of the Zeno-like freezing. Moreover, we identify a new source of memory effects which allows the persistence of non-Markovianity for long times while the excited state has already been depleted.
authors.affiliation: Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turun yliopisto, Finland.
authors.forename: Antti
authors.initials: A
authors.lastname: Karlsson
authors.affiliation: Dip. Fisica, Universitá della Calabria, 87036 Arcavacata di Rende (CS) Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Francica
authors.affiliation: Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turun yliopisto, Finland.
authors.forename: Jyrki
authors.initials: J
authors.lastname: Piilo
authors.affiliation: Dip. Fisica, Universitá della Calabria, 87036 Arcavacata di Rende (CS) Italy.|INFN - Gruppo collegato di Cosenza, 87036 Arcavacata di Rende (CS) Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Plastina