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 amultipartite 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.