Publisher’s Note: Quantum Fisher information of the Greenberger-Horne-Zeilinger state in decoherence channels [Phys. Rev. A84, 022302 (2011)]

Abstract

Publisher's Note: Quantum Fisher information of the Greenberger-Horne-Zeilinger state in decoherence channels [Phys. Rev. A 84, 022302 (2011)]

Quantum Fisher information and spin squeezing in one-axis twisting model

“…Such unitary process of equation (5) may be used to model the two-mode optical interferometry and the general Ramsey interferometry [8,36]. With equation (5), the QFI with respect of ϕ can be expressed in the following form [19,37,38,39,40]…”

Electromagnetic shielding in quantum metrology

“…On the other hand , however, interaction between a system and an environment is unavoidable in reality, and the quantum decoherence induced by such interactions may decrease the QFI and destroy the quantum entanglement in the probe system exploited to improve the precision. In this regard, It has been shown that the interaction between a system and an environment usually makes the measurements noisy, which in turn degrades the estimation precision [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

Quantum Fisher Information of Entangled Coherent States in a Lossy Mach—Zehnder Interferometer

“…This form of parameterization process is typical in interferometers. For instance, in a Ramsey interferometer H can be a collective angular momentum operator J n [27], which can be viewed as a generator of SU(2). In Mach-Zehnder interferometers, denoting a i and a † i (i=1,2) as the annihilation and creation operators for i th mode, then H can be (1) the photon number difference between two modes:…”

“…Quantum Fisher information (QFI) is another significant concept in quantum metrology and has been studied widely [20,21,22,23,24,25,26,19,27,28,29]. As an extension of the classical Fisher information in statistics and information theory, QFI plays a paramount role in quantum estimation theory.…”