Quantum coherence and parameter estimation for mixed entangled coherent states

Abstract

We study the temporal evolution of quantum coherence and parameter estimation for two-mode coherent-state superposition by using the master equation. Analytic expressions are provided and numerically displayed, which can illustrate the reliance of the coherence and Fisher information during the dynamics. Generally, we find that the amount of the quantum measures has the same behavior during the time variation, and displays a different order that depends on the different strength regimes of the input radiation fields and then disappears at infinite times. We show that these measures start from maximal value at the initial instant and decrease the time goes on. Moreover, we can observe that these measures can be protected resisted from the environment effect during the dynamics, showing an important feature of coherence and Fisher information. The obtained results can be assumed more practical in the characterization of the behavior of the coherence and Fisher information under the effect of the environment. Our observations can provide significant implications in harnessing these phenomena in quantum optics and information.