Regular Article

Dynamic of quantum Fisher information and quantum interferometric power in multipartite coherent states

¹ LPHE-Modeling and Simulation, Faculty of Sciences, University Mohammed V, Rabat, Morocco
² Department of Physics, Faculty of Sciences, University Ibn Tofail, Kenitra, Morocco
³ Abdus Salam International Centre for Theoretical physics, Trieste, Italy

^a e-mail: laghmach2006@gmail.com
^b e-mail: hanane.elhadfi@gmail.com
^c e-mail: kaydi.smp@gmail.com
^d e-mail: m_daoud@hotmail.com

Received: 29 January 2019
Revised: 14 June 2019
Published online: 3 September 2019

Abstract

We examine the role of quantum correlations, contained multipartite Glauber coherent states, in enhancing the precision in the estimation of an unknown phase shift. We give the explicit form of quantum Fisher information in even and odd multipartite coherent states. Two different pairing schemes are considered to evaluate the sensitivity of the probe state to the phase shift for some relevant local Hamiltonians. Also, a particular interest is dedicated to the derivation of the quantum interferometric power which quantifies the amount of non-classical correlations. This quantum correlations quantifier is compared with the original quantum discord built upon von Neumann entropy and we discuss the effects of quantum correlations in quantum metrology protocols. In addition, the dynamics of quantum Fisher information about a dephasing channel is studied. In order to illustrate our results, we examine the situation involving tripartite coherent states to determine the sensitivity of the probe state when the first qubit is driven by an arbitrary local Hamiltonian.