New insights of quantum Zeno phenomenon: an indirect correlation effect among subsystems

TL;DR

This paper reveals how indirect correlations among subsystems influence the quantum Zeno effect and decay dynamics, especially under continuous and pulsed measurements, through a three-subsystem perturbation theory approach.

Contribution

It introduces a new mechanism involving indirect correlations that affect decay rates and quantum Zeno phenomena in systems coupled to a continuum reservoir.

Findings

Indirect correlation causes Rabi-like inter-modulation among subsystems.

Decay rates vary significantly between continuous and pulsed measurements.

System dynamics are strongly affected by measurement parameters such as Rabi strength and pulse rate.

Abstract

Frequent Measurements on an unstable particle located at observable initial state freeze the particle on this state, known as quantum Zeno effect [1-14]. Measurements on an observable subspace further open the prelude of quantum Zeno dynamics [15-17]. These phenomena affect the results of quantum measurement that has been widely used in quantum information and quantum computation [18-21]. However, this common argument is insufficient when the initial state is coupled with a continuum reservoir. In such an irreversible system, intrinsic decay property destroys the frozen behavior. Although it has been proven that the decay rate of the initial state will be affected by measurements [7], the knowledge of detailed mechanisms for this measurement-dependent decay is still limited. In this work, we found based on three-subsystem perturbation theory that the indirect correlation between a continuum reservoir and a measurement apparatus through the interaction with a quantum system causes a Rabi-like inter-modulation among these subsystems. The indirect correlation effect from this combination drives the system into quantum Zeno and reactivation regions, which are dependent upon the Rabi strength, pulse duty, and its repetition rate. We also found that the dynamical changes of decay rate are quite different in continuous and pulsed measurements, and, thus, significantly affect the dynamics of the system.