Zeno dynamics in quantum open systems

TL;DR

This paper explores how noise and non-Markovian effects influence the quantum Zeno effect in open systems, providing formulas for Fisher information and bounds on Zeno time, with implications for quantum metrology.

Contribution

It introduces a method to analyze quantum Zeno dynamics under noisy conditions using noisy Fisher information and derives bounds on Zeno time in open quantum systems.

Findings

Non-Markovian noise impacts quantum Zeno effect analysis.

Exact forms of dissipative Fisher information are derived.

Noise can enhance Zeno dynamics in entangled states.

Abstract

Quantum Zeno effect shows that frequent observations can slow down or even stop the unitary time evolution of an unstable quantum system. This effect can also be regarded as a physical consequence of the the statistical indistinguishability of neighboring quantum states. The accessibility of quantum Zeno dynamics under unitary time evolution can be quantitatively estimated by quantum Zeno time in terms of Fisher information. In this work, we investigate the accessibility of quantum Zeno dynamics in quantum open systems by calculating noisy Fisher information, in which a trace preserving and completely positive map is assumed. We firstly study the consequences of non-Markovian noise on quantum Zeno effect and give the exact forms of the dissipative Fisher information and the quantum Zeno time. Then, for the operator-sum representation, an achievable upper bound of the quantum Zeno time is given with the help of the results in noisy quantum metrology. It is of significance that the noise affecting the accuracy in the entanglement-enhanced parameter estimation can conversely be favorable for the accessibility of quantum Zeno dynamics of entangled states.