Influence of monitoring efficiency on states protection using partial measurement and quantum reversal
Longfei Fan, Muhammad Suhail Zubairy · Journal of Physics B Atomic Molecular and Optical Physics · 2016
Abstract In a recent protocol, partial measurement and quantum reversal are combined to suppress amplitude-damping decoherence. In the protocol, quantum states are monitored and then collapsed ones discarded before further processes. However, ideal monitoring efficiency is assumed in these recent studies. Here we study the protection of single-qubit states and two-qubit entangled states against amplitude-damping using the protocol under finite-monitoring efficiency. Fidelity and concurrence are evaluated to quantify the effect of protection. We show that the effect is weakened distinctly and affected by various parameters. It even becomes worse in conditions where protection with ideal efficiency can obtain the best effect. A criterion for deciding whether to apply the protocol is given. The parameters to obtain optimal effect are also studied.