Zeno-anti-Zeno crossover dynamics in a spin-boson system

We examine the critical system parameters which affect the quantum Zeno-anti-Zeno transition in a spin-boson system by applying the notion of correlated Zeno subspaces beyond the qubit system to its decayed part represented by a collective reservoir of oscillators. We also examine the effect of coherent control via a periodic sequence of dynamical decoupling pulses prior to projective measurement. Our results show that depending on the system bias and measurement time interval of the spin-boson model, coherent control via periodic dynamical decoupling pulses eliminates the Zeno-anti-Zeno transition behavior. We extend the calculations to examine the entanglement dynamics of two initially entangled qubits coupled to independent reservoirs with varying configuration and subjected to frequent measurements. In a multipartite system, in which one or more qubit-reservoir system can undergo the Zeno-anti-Zeno transition, we show that the effects of measurements made in a one qubit-reservoir subsystem can reverberate noticeably throughout a whole array of N pairs of qubit-reservoir subsystems.