Control of Decoherence in different environments : A case study for dissipative magneto-oscillator

In this paper, we analyze two different techniques based on reservoir engineering method and quantum Zeno effect for controlling decoherence of a dissipative charged oscillator in the presence of an external magnetic field. Our main focus is to investigate the sensitiveness of these decoherence control techniques on the details of different environmental spectrum (J(ω)), and on the crucial role played by different system and reservoir parameters, e.g., external magnetic field $r_c$, confinement length $r₀$, temperature (T), cut-off frequency of reservoir spectrum $ω_cut$, and measurement interval (τ). First, we consider the charged quantum oscillator in an initial nonclassical Schrodinger cat state and analyze the non-Markovian dynamics for the magneto-oscillator in contact with Ohmic, sub-Ohmic, and super-Ohmic environments. We show the procedure to control the quantumness of the Schrodinger cat state by tuning the parameters r_c, r₀, and J(ω). On the other hand, we investigate the effect of nonselective energy measurement process on the mortification of quantumness of an initial Fock-Darwin state of the charged magneto-oscillator. We investigate in details the strategy to manipulate the continuous passage from decay suppression to decay acceleration by engineered reservoirs and by tuning the system or reservoir parameters, e.g., r_c, r₀, T or τ. As a result of that one can control environment induced decoherence (EID).